« get me outta code hell

hsmusic-wiki - HSMusic - static wiki software cataloguing collaborative creation
about summary refs log tree commit diff
path: root/src/upd8.js
diff options
context:
space:
mode:
Diffstat (limited to 'src/upd8.js')
-rwxr-xr-xsrc/upd8.js1385
1 files changed, 1135 insertions, 250 deletions
diff --git a/src/upd8.js b/src/upd8.js
index 9e4ef4fb..86ecab69 100755
--- a/src/upd8.js
+++ b/src/upd8.js
@@ -34,22 +34,24 @@
 import '#import-heck';
 
 import {execSync} from 'node:child_process';
-import {readdir, readFile, stat} from 'node:fs/promises';
+import {readdir, readFile, stat, writeFile} from 'node:fs/promises';
 import * as path from 'node:path';
 import {fileURLToPath} from 'node:url';
 
 import wrap from 'word-wrap';
 
-import {mapAggregate, showAggregate} from '#aggregate';
+import {mapAggregate, openAggregate, showAggregate} from '#aggregate';
 import CacheableObject from '#cacheable-object';
+import {stringifyCache} from '#cli';
 import {displayCompositeCacheAnalysis} from '#composite';
-import {bindFind, getAllFindSpecs} from '#find';
+import find, {bindFind, getAllFindSpecs} from '#find';
 import {processLanguageFile, watchLanguageFile, internalDefaultStringsFile}
   from '#language';
 import {isMain, traverse} from '#node-utils';
+import {bindReverse} from '#reverse';
 import {writeSearchData} from '#search';
 import {sortByName} from '#sort';
-import {generateURLs, urlSpec} from '#urls';
+import thingConstructors from '#things';
 import {identifyAllWebRoutes} from '#web-routes';
 
 import {
@@ -66,13 +68,15 @@ import {
 
 import {
   filterReferenceErrors,
-  reportDirectoryErrors,
   reportContentTextErrors,
+  reportDirectoryErrors,
+  reportOrphanedArtworks,
 } from '#data-checks';
 
 import {
   bindOpts,
   empty,
+  filterMultipleArrays,
   indentWrap as unboundIndentWrap,
   withEntries,
 } from '#sugar';
@@ -87,6 +91,15 @@ import genThumbs, {
 } from '#thumbs';
 
 import {
+  applyLocalizedWithBaseDirectory,
+  applyURLSpecOverriding,
+  generateURLs,
+  getOrigin,
+  internalDefaultURLSpecFile,
+  processURLSpecFromFile,
+} from '#urls';
+
+import {
   getAllDataSteps,
   linkWikiDataArrays,
   loadYAMLDocumentsFromDataSteps,
@@ -122,7 +135,8 @@ const defaultStepStatus = {status: STATUS_NOT_STARTED, annotation: null};
 // Defined globally for quick access outside the main() function's contents.
 // This will be initialized and mutated over the course of main().
 let stepStatusSummary;
-let showStepStatusSummary = false;
+let shouldShowStepStatusSummary = false;
+let shouldShowStepMemoryInSummary = false;
 
 async function main() {
   Error.stackTraceLimit = Infinity;
@@ -138,8 +152,8 @@ async function main() {
       {...defaultStepStatus, name: `migrate thumbnails`,
         for: ['thumbs']},
 
-    loadThumbnailCache:
-      {...defaultStepStatus, name: `load thumbnail cache file`,
+    loadOfflineThumbnailCache:
+      {...defaultStepStatus, name: `load offline thumbnail cache file`,
         for: ['thumbs', 'build']},
 
     generateThumbnails:
@@ -162,6 +176,10 @@ async function main() {
       {...defaultStepStatus, name: `report directory errors`,
         for: ['verify']},
 
+    reportOrphanedArtworks:
+      {...defaultStepStatus, name: `report orphaned artworks`,
+        for: ['verify']},
+
     filterReferenceErrors:
       {...defaultStepStatus, name: `filter reference errors`,
         for: ['verify']},
@@ -178,6 +196,21 @@ async function main() {
       {...defaultStepStatus, name: `precache nearly all data`,
         for: ['build']},
 
+    sortWikiDataSourceFiles:
+      {...defaultStepStatus, name: `apply sorting rules to wiki data files`,
+        for: ['build']},
+
+    checkWikiDataSourceFileSorting:
+      {...defaultStepStatus, name: `check sorting rules against wiki data files`},
+
+    loadURLFiles:
+      {...defaultStepStatus, name: `load internal & custom url spec files`,
+        for: ['build']},
+
+    loadOnlineThumbnailCache:
+      {...defaultStepStatus, name: `load online thumbnail cache file`,
+        for: ['thumbs', 'build']},
+
     // TODO: This should be split into load/watch steps.
     loadInternalDefaultLanguage:
       {...defaultStepStatus, name: `load internal default language`,
@@ -203,6 +236,10 @@ async function main() {
       {...defaultStepStatus, name: `preload file sizes`,
         for: ['build']},
 
+    loadOnlineFileSizeCache:
+      {...defaultStepStatus, name: `load online file size cache file`,
+        for: ['build']},
+
     buildSearchIndex:
       {...defaultStepStatus, name: `generate search index`,
         for: ['build', 'search']},
@@ -246,6 +283,35 @@ async function main() {
     }));
 
   let selectedBuildModeFlag;
+  let sortInAdditionToBuild = false;
+
+  // As an exception, --sort can be combined with another build mode.
+  if (selectedBuildModeFlags.length >= 2 && selectedBuildModeFlags.includes('sort')) {
+    sortInAdditionToBuild = true;
+    selectedBuildModeFlags.splice(selectedBuildModeFlags.indexOf('sort'), 1);
+  }
+
+  if (sortInAdditionToBuild) {
+    Object.assign(stepStatusSummary.sortWikiDataSourceFiles, {
+      status: STATUS_NOT_STARTED,
+      annotation: `--sort provided with another build mode`,
+    });
+
+    Object.assign(stepStatusSummary.checkWikiDataSourceFileSorting, {
+      status: STATUS_NOT_APPLICABLE,
+      annotation: `--sort provided, dry run not applicable`,
+    });
+  } else {
+    Object.assign(stepStatusSummary.sortWikiDataSourceFiles, {
+      status: STATUS_NOT_APPLICABLE,
+      annotation: `--sort not provided, dry run only`,
+    });
+
+    Object.assign(stepStatusSummary.checkWikiDataSourceFileSorting, {
+      status: STATUS_NOT_STARTED,
+      annotation: `--sort not provided, dry run applicable`,
+    });
+  }
 
   if (empty(selectedBuildModeFlags)) {
     // No build mode selected. This is not a valid state for building the wiki,
@@ -323,11 +389,36 @@ async function main() {
       type: 'value',
     },
 
+    'urls': {
+      help: `Specify which optional URL specs to use for this build, customizing where pages are generated or resources are accessed from`,
+      type: 'value',
+    },
+
+    'show-url-spec': {
+      help: `Displays the entire computed URL spec, after the data folder's default override and optional specs are applied. This is mostly useful for progammer debugging!`,
+      type: 'flag',
+    },
+
+    'skip-directory-validation': {
+      help: `Skips checking for duplicated directories, which speeds up the build but may cause the wiki to catch on fire`,
+      type: 'flag',
+    },
+
+    'skip-orphaned-artwork-validation': {
+      help: `Skips checking for internally orphaned artworks, which is a bad idea, unless you're debugging those in particular`,
+      type: 'flag',
+    },
+
     'skip-reference-validation': {
       help: `Skips checking and reporting reference errors, which speeds up the build but may silently allow erroneous data to pass through`,
       type: 'flag',
     },
 
+    'skip-content-text-validation': {
+      help: `Skips checking and reporting content text errors, which speeds up the build but may silently allow misformatted or mislinked content to pass through`,
+      type: 'flag',
+    },
+
     // Thum8nail gener8tion is *usually* something you want, 8ut it can 8e
     // kinda a pain to run every time, since it does necessit8te reading
     // every media file at run time. Pass this to skip it.
@@ -353,11 +444,26 @@ async function main() {
       type: 'flag',
     },
 
+    'refresh-online-thumbs': {
+      help: `Downloads a fresh copy of the online file size cache, so changes there are immediately reflected`,
+      type: 'flag',
+    },
+
     'skip-file-sizes': {
       help: `Skips preloading file sizes for images and additional files, which will be left blank in the build`,
       type: 'flag',
     },
 
+    'refresh-online-file-sizes': {
+      help: `Downloads a fresh copy of the online file size cache, so changes there are immediately reflected`,
+      type: 'flag',
+    },
+
+    'skip-sorting-validation': {
+      help: `Skips checking the if custom sorting rules for this wiki are satisfied`,
+      type: 'flag',
+    },
+
     'skip-media-validation': {
       help: `Skips checking and reporting missing and misplaced media files, which isn't necessary if you aren't adding or removing data or updating directories`,
       type: 'flag',
@@ -407,6 +513,11 @@ async function main() {
       type: 'flag',
     },
 
+    'show-step-memory': {
+      help: `Include total process memory usage traces at the time each top-level build step ends. Use with --show-step-summary. This is mostly useful for programmer debugging!`,
+      type: 'flag',
+    },
+
     'queue-size': {
       help: `Process more or fewer disk files at once to optimize performance or avoid I/O errors, unlimited if set to 0 (between 500 and 700 is usually a safe range for building HSMusic on Windows machines)\nDefaults to ${defaultQueueSize}`,
       type: 'value',
@@ -429,14 +540,6 @@ async function main() {
     },
     magick: {alias: 'magick-threads'},
 
-    // This option is super slow and has the potential for bugs! It puts
-    // CacheableObject in a mode where every instance is a Proxy which will
-    // keep track of invalid property accesses.
-    'show-invalid-property-accesses': {
-      help: `Report accesses at runtime to nonexistant properties on wiki data objects, at a dramatic performance cost\n(Internal/development use only)`,
-      type: 'flag',
-    },
-
     'precache-mode': {
       help:
         `Change the way certain runtime-computed values are preemptively evaluated and cached\n\n` +
@@ -474,7 +577,8 @@ async function main() {
     ...buildOptions,
   });
 
-  showStepStatusSummary = cliOptions['show-step-summary'] ?? false;
+  shouldShowStepStatusSummary = cliOptions['show-step-summary'] ?? false;
+  shouldShowStepMemoryInSummary = cliOptions['show-step-memory'] ?? false;
 
   if (cliOptions['help']) {
     console.log(
@@ -555,7 +659,9 @@ async function main() {
   const showAggregateTraces = cliOptions['show-traces'] ?? false;
 
   const precacheMode = cliOptions['precache-mode'] ?? 'common';
-  const showInvalidPropertyAccesses = cliOptions['show-invalid-property-accesses'] ?? false;
+
+  const wantedURLSpecKeys = cliOptions['urls'] ?? [];
+  const showURLSpec = cliOptions['show-url-spec'] ?? false;
 
   // Makes writing nicer on the CPU and file I/O parts of the OS, with a
   // marginal performance deficit while waiting for file writes to finish
@@ -651,9 +757,13 @@ async function main() {
       step.annotation = `--${cliFlag} provided`;
 
       if (cliFlagWarning) {
+        if (!paragraph) console.log('');
+
         for (const line of cliFlagWarning.split('\n')) {
           logWarn(line);
         }
+
+        paragraph = false;
       }
 
       for (const step of cliFlagDisablesSteps) {
@@ -732,6 +842,27 @@ async function main() {
       }
     };
 
+    fallbackStep('reportDirectoryErrors', {
+      default: 'perform',
+      cli: {
+        flag: 'skip-directory-validation',
+        negate: true,
+        warn:
+          `Skipping directory validation. If any directories are duplicated\n` +
+          `in data, the build will probably fail in unpredictable ways.`,
+      },
+    });
+
+    fallbackStep('reportOrphanedArtworks', {
+      default: 'perform',
+      cli: {
+        flag: 'skip-orphaned-artwork-validation',
+        negate: true,
+        warn:
+          `Skipping orphaned artwork validation. Hopefully you're debugging!`,
+      },
+    });
+
     fallbackStep('filterReferenceErrors', {
       default: 'perform',
       cli: {
@@ -740,7 +871,19 @@ async function main() {
         warn:
           `Skipping reference validation. If any reference errors are present\n` +
           `in data, they will be silently passed along to the build.`,
-      }
+      },
+    });
+
+    fallbackStep('reportContentTextErrors', {
+      default: 'perform',
+      cli: {
+        flag: 'skip-content-text-validation',
+        negate: true,
+        warn:
+          `Skipping content text validation. If any commentary or other content\n` +
+          `is misformatted or has bad links, it will be silently passed along\n` +
+          `to the build.`,
+      },
     });
 
     fallbackStep('generateThumbnails', {
@@ -851,20 +994,32 @@ async function main() {
         logInfo`Next scheduled is in ${whenst(delay - delta)}, or by using ${'--refresh-search'}.`;
         Object.assign(stepStatusSummary.buildSearchIndex, {
           status: STATUS_NOT_APPLICABLE,
-          annotation: `earlier than scheduled based on file mtime`,
+          annotation: `earlier than scheduled`,
         });
       } else {
         logInfo`Search index hasn't been generated for a little while.`;
         logInfo`It'll be generated this build, then again in ${whenst(delay)}.`;
         Object.assign(stepStatusSummary.buildSearchIndex, {
           status: STATUS_NOT_STARTED,
-          annotation: `past when shceduled based on file mtime`,
+          annotation: `past when shceduled`,
         });
       }
 
       paragraph = false;
     }
 
+    fallbackStep('checkWikiDataSourceFileSorting', {
+      default: 'perform',
+      buildConfig: 'sort',
+      cli: {
+        flag: 'skip-sorting-validation',
+        negate: true,
+        warning:
+          `Skipping sorting validation. If any of this wiki's sorting rules are not\n` +
+          `satisfied, those errors will be silently passed along to the build.`,
+      },
+    });
+
     fallbackStep('verifyImagePaths', {
       default: 'perform',
       buildConfig: 'mediaValidation',
@@ -892,7 +1047,7 @@ async function main() {
   }
 
   if (stepStatusSummary.generateThumbnails.status === STATUS_NOT_STARTED) {
-    Object.assign(stepStatusSummary.loadThumbnailCache, {
+    Object.assign(stepStatusSummary.loadOfflineThumbnailCache, {
       status: STATUS_NOT_APPLICABLE,
       annotation: `using cache from thumbnail generation`,
     });
@@ -1044,6 +1199,7 @@ async function main() {
           status: STATUS_FATAL_ERROR,
           annotation: `--new-thumbs provided but regeneration not needed`,
           timeEnd: Date.now(),
+          memory: process.memoryUsage(),
         });
 
         return false;
@@ -1059,6 +1215,7 @@ async function main() {
           status: STATUS_FATAL_ERROR,
           annotation: mediaCachePathAnnotation,
           timeEnd: Date.now(),
+          memory: process.memoryUsage(),
         });
 
         return false;
@@ -1125,6 +1282,7 @@ async function main() {
       status: STATUS_FATAL_ERROR,
       annotation: mediaCachePathAnnotation,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     return false;
@@ -1136,6 +1294,7 @@ async function main() {
     status: STATUS_DONE_CLEAN,
     annotation: mediaCachePathAnnotation,
     timeEnd: Date.now(),
+    memory: process.memoryUsage(),
   });
 
   if (stepStatusSummary.migrateThumbnails.status === STATUS_NOT_STARTED) {
@@ -1155,6 +1314,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -1166,6 +1326,7 @@ async function main() {
     Object.assign(stepStatusSummary.migrateThumbnails, {
       status: STATUS_DONE_CLEAN,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     return true;
@@ -1180,16 +1341,17 @@ async function main() {
   };
 
   if (
-    stepStatusSummary.loadThumbnailCache.status === STATUS_NOT_STARTED &&
+    stepStatusSummary.loadOfflineThumbnailCache.status === STATUS_NOT_STARTED &&
     stepStatusSummary.generateThumbnails.status === STATUS_NOT_STARTED
   ) {
-    throw new Error(`Unable to continue with both loadThumbnailCache and generateThumbnails`);
+    throw new Error(`Unable to continue with both loadOfflineThumbnailCache and generateThumbnails`);
   }
 
   let thumbsCache;
 
-  if (stepStatusSummary.loadThumbnailCache.status === STATUS_NOT_STARTED) {
-    Object.assign(stepStatusSummary.loadThumbnailCache, {
+  // TODO: Skip this step if we're using online thumbs
+  if (stepStatusSummary.loadOfflineThumbnailCache.status === STATUS_NOT_STARTED) {
+    Object.assign(stepStatusSummary.loadOfflineThumbnailCache, {
       status: STATUS_STARTED_NOT_DONE,
       timeStart: Date.now(),
     });
@@ -1205,10 +1367,11 @@ async function main() {
         logError`that you'll be good to go and don't need to process thumbnails`
         logError`again!`;
 
-        Object.assign(stepStatusSummary.loadThumbnailCache, {
+        Object.assign(stepStatusSummary.loadOfflineThumbnailCache, {
           status: STATUS_FATAL_ERROR,
           annotation: `cache does not exist`,
           timeEnd: Date.now(),
+          memory: process.memoryUsage(),
         });
 
         return false;
@@ -1222,10 +1385,11 @@ async function main() {
         logError`to help you out with troubleshooting!`;
         logError`${'https://hsmusic.wiki/discord/'}`;
 
-        Object.assign(stepStatusSummary.loadThumbnailCache, {
+        Object.assign(stepStatusSummary.loadOfflineThumbnailCache, {
           status: STATUS_FATAL_ERROR,
           annotation: `cache malformed or unreadable`,
           timeEnd: Date.now(),
+          memory: process.memoryUsage(),
         });
 
         return false;
@@ -1234,9 +1398,10 @@ async function main() {
 
     logInfo`Thumbnail cache file successfully read.`;
 
-    Object.assign(stepStatusSummary.loadThumbnailCache, {
+    Object.assign(stepStatusSummary.loadOfflineThumbnailCache, {
       status: STATUS_DONE_CLEAN,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     logInfo`Skipping thumbnail generation.`;
@@ -1264,6 +1429,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -1272,6 +1438,7 @@ async function main() {
     Object.assign(stepStatusSummary.generateThumbnails, {
       status: STATUS_DONE_CLEAN,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     if (thumbsOnly) {
@@ -1283,10 +1450,6 @@ async function main() {
     thumbsCache = {};
   }
 
-  if (showInvalidPropertyAccesses) {
-    CacheableObject.DEBUG_SLOW_TRACK_INVALID_PROPERTIES = true;
-  }
-
   Object.assign(stepStatusSummary.loadDataFiles, {
     status: STATUS_STARTED_NOT_DONE,
     timeStart: Date.now(),
@@ -1309,6 +1472,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `javascript error - view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -1348,6 +1512,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `error loading data files`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -1389,6 +1554,10 @@ async function main() {
           ? prop
           : wikiData[prop]);
 
+      if (array && empty(array)) {
+        return;
+      }
+
       logInfo` - ${array?.length ?? colors.red('(Missing!)')} ${colors.normal(colors.dim(label))}`;
     }
 
@@ -1415,9 +1584,14 @@ async function main() {
         logThings('newsData', 'news entries');
       }
       logThings('staticPageData', 'static pages');
+      logThings('sortingRules', 'sorting rules');
       if (wikiData.homepageLayout) {
         logInfo` - ${1} homepage layout (${
-          wikiData.homepageLayout.rows.length
+          wikiData.homepageLayout.sections.length
+        } sections, ${
+          wikiData.homepageLayout.sections
+            .flatMap(section => section.rows)
+            .length
         } rows)`;
       }
       if (wikiData.wikiInfo) {
@@ -1450,6 +1624,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `wiki info object not available`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -1462,6 +1637,7 @@ async function main() {
       Object.assign(stepStatusSummary.loadDataFiles, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } else {
       logWarn`This might indicate some fields in the YAML data weren't formatted`;
@@ -1476,6 +1652,7 @@ async function main() {
         status: STATUS_HAS_WARNINGS,
         annotation: `view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     }
   }
@@ -1489,11 +1666,12 @@ async function main() {
     timeStart: Date.now(),
   });
 
-  linkWikiDataArrays(wikiData);
+  linkWikiDataArrays(wikiData, {bindFind, bindReverse});
 
   Object.assign(stepStatusSummary.linkWikiDataArrays, {
     status: STATUS_DONE_CLEAN,
     timeEnd: Date.now(),
+    memory: process.memoryUsage(),
   });
 
   if (precacheMode === 'common') {
@@ -1565,6 +1743,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `see log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -1573,51 +1752,88 @@ async function main() {
     Object.assign(stepStatusSummary.precacheCommonData, {
       status: STATUS_DONE_CLEAN,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
   }
 
-  const urls = generateURLs(urlSpec);
+  // Check for things with duplicate directories throughout the data,
+  // and halt if any are found.
 
-  // Filter out any things with duplicate directories throughout the data,
-  // warning about them too.
+  if (stepStatusSummary.reportDirectoryErrors.status === STATUS_NOT_STARTED) {
+    Object.assign(stepStatusSummary.reportDirectoryErrors, {
+      status: STATUS_STARTED_NOT_DONE,
+      timeStart: Date.now(),
+    });
 
-  Object.assign(stepStatusSummary.reportDirectoryErrors, {
-    status: STATUS_STARTED_NOT_DONE,
-    timeStart: Date.now(),
-  });
+    try {
+      reportDirectoryErrors(wikiData, {getAllFindSpecs});
+      logInfo`No duplicate directories found - nice!`;
+      paragraph = false;
 
-  try {
-    reportDirectoryErrors(wikiData, {getAllFindSpecs});
-    logInfo`No duplicate directories found - nice!`;
-    paragraph = false;
+      Object.assign(stepStatusSummary.reportDirectoryErrors, {
+        status: STATUS_DONE_CLEAN,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+    } catch (aggregate) {
+      if (!paragraph) console.log('');
+      niceShowAggregate(aggregate);
 
-    Object.assign(stepStatusSummary.reportDirectoryErrors, {
-      status: STATUS_DONE_CLEAN,
-      timeEnd: Date.now(),
-    });
-  } catch (aggregate) {
-    if (!paragraph) console.log('');
-    niceShowAggregate(aggregate);
+      logWarn`The above duplicate directories were detected while reviewing data files.`;
+      logWarn`Since it's impossible to automatically determine which one's directory is`;
+      logWarn`correct, the build can't continue. Specify unique 'Directory' fields in`;
+      logWarn`some or all of these data entries to resolve the errors.`;
 
-    logWarn`The above duplicate directories were detected while reviewing data files.`;
-    logWarn`Since it's impossible to automatically determine which one's directory is`;
-    logWarn`correct, the build can't continue. Specify unique 'Directory' fields in`;
-    logWarn`some or all of these data entries to resolve the errors.`;
+      console.log('');
+      paragraph = true;
 
-    console.log('');
-    paragraph = true;
+      Object.assign(stepStatusSummary.reportDirectoryErrors, {
+        status: STATUS_FATAL_ERROR,
+        annotation: `duplicate directories found`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
 
-    Object.assign(stepStatusSummary.reportDirectoryErrors, {
-      status: STATUS_FATAL_ERROR,
-      annotation: `duplicate directories found`,
-      timeEnd: Date.now(),
+      return false;
+    }
+  }
+
+  // Check for artwork objects which have been orphaned from their things,
+  // and halt if any are found.
+
+  if (stepStatusSummary.reportOrphanedArtworks.status === STATUS_NOT_STARTED) {
+    Object.assign(stepStatusSummary.reportOrphanedArtworks, {
+      status: STATUS_STARTED_NOT_DONE,
+      timeStart: Date.now(),
     });
 
-    return false;
+    try {
+      reportOrphanedArtworks(wikiData, {getAllFindSpecs});
+
+      Object.assign(stepStatusSummary.reportOrphanedArtworks, {
+        status: STATUS_DONE_CLEAN,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+    } catch (aggregate) {
+      if (!paragraph) console.log('');
+      niceShowAggregate(aggregate);
+
+      logError`Failed to initialize artwork data connections properly.`;
+      fileIssue();
+
+      Object.assign(stepStatusSummary.reportOrphanedArtworks, {
+        status: STATUS_FATAL_ERROR,
+        annotation: `orphaned artworks found`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+
+      return false;
+    }
   }
 
-  // Filter out any reference errors throughout the data, warning about them
-  // too.
+  // Filter out any reference errors throughout the data, warning about these.
 
   if (stepStatusSummary.filterReferenceErrors.status === STATUS_NOT_STARTED) {
     Object.assign(stepStatusSummary.filterReferenceErrors, {
@@ -1626,7 +1842,7 @@ async function main() {
     });
 
     const filterReferenceErrorsAggregate =
-      filterReferenceErrors(wikiData, {bindFind});
+      filterReferenceErrors(wikiData, {find, bindFind});
 
     try {
       filterReferenceErrorsAggregate.close();
@@ -1637,6 +1853,7 @@ async function main() {
       Object.assign(stepStatusSummary.filterReferenceErrors, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } catch (error) {
       if (!paragraph) console.log('');
@@ -1654,6 +1871,7 @@ async function main() {
         status: STATUS_HAS_WARNINGS,
         annotation: `view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     }
   }
@@ -1673,6 +1891,7 @@ async function main() {
       Object.assign(stepStatusSummary.reportContentTextErrors, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } catch (error) {
       if (!paragraph) console.log('');
@@ -1689,6 +1908,7 @@ async function main() {
         status: STATUS_HAS_WARNINGS,
         annotation: `view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     }
   }
@@ -1701,11 +1921,12 @@ async function main() {
     timeStart: Date.now(),
   });
 
-  sortWikiDataArrays(yamlDataSteps, wikiData);
+  sortWikiDataArrays(yamlDataSteps, wikiData, {bindFind, bindReverse});
 
   Object.assign(stepStatusSummary.sortWikiDataArrays, {
     status: STATUS_DONE_CLEAN,
     timeEnd: Date.now(),
+    memory: process.memoryUsage(),
   });
 
   if (precacheMode === 'all') {
@@ -1729,9 +1950,81 @@ async function main() {
     Object.assign(stepStatusSummary.precacheAllData, {
       status: STATUS_DONE_CLEAN,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
   }
 
+  if (stepStatusSummary.sortWikiDataSourceFiles.status === STATUS_NOT_STARTED) {
+    Object.assign(stepStatusSummary.sortWikiDataSourceFiles, {
+      status: STATUS_STARTED_NOT_DONE,
+      timeStart: Date.now(),
+    });
+
+    const {SortingRule} = thingConstructors;
+    const results =
+      await Array.fromAsync(SortingRule.go({dataPath, wikiData}));
+
+    if (results.some(result => result.changed)) {
+      logInfo`Updated data files to satisfy sorting.`;
+      logInfo`Restarting automatically, since that's now needed!`;
+
+      Object.assign(stepStatusSummary.sortWikiDataSourceFiles, {
+        status: STATUS_DONE_CLEAN,
+        annotation: `changes cueing restart`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+
+      return 'restart';
+    } else {
+      logInfo`All sorting rules are satisfied. Nice!`;
+      paragraph = false;
+
+      Object.assign(stepStatusSummary.sortWikiDataSourceFiles, {
+        status: STATUS_DONE_CLEAN,
+        annotation: `no changes needed`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+    }
+  } else if (stepStatusSummary.checkWikiDataSourceFileSorting.status === STATUS_NOT_STARTED) {
+    Object.assign(stepStatusSummary.checkWikiDataSourceFileSorting, {
+      status: STATUS_STARTED_NOT_DONE,
+      timeStart: Date.now(),
+    });
+
+    const {SortingRule} = thingConstructors;
+    const results =
+      await Array.fromAsync(SortingRule.go({dataPath, wikiData, dry: true}));
+
+    const needed = results.filter(result => result.changed);
+
+    if (empty(needed)) {
+      logInfo`All sorting rules are satisfied. Nice!`;
+      paragraph = false;
+
+      Object.assign(stepStatusSummary.checkWikiDataSourceFileSorting, {
+        status: STATUS_DONE_CLEAN,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+    } else {
+      logWarn`Some of this wiki's sorting rules currently aren't satisfied:`;
+      for (const {rule} of needed) {
+        logWarn`- ${rule.message}`;
+      }
+      logWarn`Run ${'hsmusic --sort'} to automatically update data files.`;
+      paragraph = false;
+
+      Object.assign(stepStatusSummary.checkWikiDataSourceFileSorting, {
+        status: STATUS_HAS_WARNINGS,
+        annotation: `not all rules satisfied`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+    }
+  }
+
   if (stepStatusSummary.performBuild.status === STATUS_NOT_APPLICABLE) {
     displayCompositeCacheAnalysis();
 
@@ -1740,6 +2033,354 @@ async function main() {
     }
   }
 
+  Object.assign(stepStatusSummary.loadURLFiles, {
+    status: STATUS_STARTED_NOT_DONE,
+    timeStart: Date.now(),
+  });
+
+  let internalURLSpec = {};
+
+  try {
+    let aggregate;
+    ({aggregate, result: internalURLSpec} =
+      await processURLSpecFromFile(internalDefaultURLSpecFile));
+
+    aggregate.close();
+  } catch (error) {
+    niceShowAggregate(error);
+    logError`Couldn't load internal default URL spec.`;
+    logError`This is required to build the wiki, so stopping here.`;
+    fileIssue();
+
+    Object.assign(stepStatusSummary.loadURLFiles, {
+      status: STATUS_FATAL_ERROR,
+      annotation: `see log for details`,
+      timeEnd: Date.now(),
+      memory: process.memoryUsage(),
+    });
+
+    return false;
+  }
+
+  // We'll mutate this as we load other url spec files.
+  const urlSpec = structuredClone(internalURLSpec);
+
+  const allURLSpecDataFiles =
+    (await readdir(dataPath))
+      .filter(name =>
+        name.startsWith('urls') &&
+        ['.json', '.yaml'].includes(path.extname(name)))
+      .sort() /* Just in case... */
+      .map(name => path.join(dataPath, name));
+
+  const getURLSpecKeyFromFile = file => {
+    const base = path.basename(file, path.extname(file));
+    if (base === 'urls') {
+      return base;
+    } else {
+      return base.replace(/^urls-/, '');
+    }
+  };
+
+  const isDefaultURLSpecFile = file =>
+    getURLSpecKeyFromFile(file) === 'urls';
+
+  const overrideDefaultURLSpecFile =
+    allURLSpecDataFiles.find(file => isDefaultURLSpecFile(file));
+
+  const optionalURLSpecDataFiles =
+    allURLSpecDataFiles.filter(file => !isDefaultURLSpecFile(file));
+
+  const optionalURLSpecDataKeys =
+    optionalURLSpecDataFiles.map(file => getURLSpecKeyFromFile(file));
+
+  const selectedURLSpecDataKeys = optionalURLSpecDataKeys.slice();
+  const selectedURLSpecDataFiles = optionalURLSpecDataFiles.slice();
+
+  const {removed: [unusedURLSpecDataKeys]} =
+    filterMultipleArrays(
+      selectedURLSpecDataKeys,
+      selectedURLSpecDataFiles,
+      (key, _file) => wantedURLSpecKeys.includes(key));
+
+  if (!empty(selectedURLSpecDataKeys)) {
+    logInfo`Using these optional URL specs: ${selectedURLSpecDataKeys.join(', ')}`;
+    if (!empty(unusedURLSpecDataKeys)) {
+      logInfo`Other available optional URL specs: ${unusedURLSpecDataKeys.join(', ')}`;
+    }
+  } else if (!empty(unusedURLSpecDataKeys)) {
+    logInfo`Not using any optional URL specs.`;
+    logInfo`These are available with --urls: ${unusedURLSpecDataKeys.join(', ')}`;
+  }
+
+  if (overrideDefaultURLSpecFile) {
+    try {
+      let aggregate;
+      let overrideDefaultURLSpec;
+
+      ({aggregate, result: overrideDefaultURLSpec} =
+          await processURLSpecFromFile(overrideDefaultURLSpecFile));
+
+      aggregate.close();
+
+      ({aggregate} =
+          applyURLSpecOverriding(overrideDefaultURLSpec, urlSpec));
+
+      aggregate.close();
+    } catch (error) {
+      niceShowAggregate(error);
+      logError`Errors loading this data repo's ${'urls.yaml'} file.`;
+      logError`This provides essential overrides for this wiki,`;
+      logError`so stopping here. Debug the errors to continue.`;
+
+      Object.assign(stepStatusSummary.loadURLFiles, {
+        status: STATUS_FATAL_ERROR,
+        annotation: `see log for details`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+
+      return false;
+    }
+  }
+
+  const processURLSpecsAggregate =
+    openAggregate({message: `Errors processing URL specs`});
+
+  const selectedURLSpecs =
+    processURLSpecsAggregate.receive(
+      await Promise.all(
+        selectedURLSpecDataFiles
+          .map(file => processURLSpecFromFile(file))));
+
+  for (const selectedURLSpec of selectedURLSpecs) {
+    processURLSpecsAggregate.receive(
+      applyURLSpecOverriding(selectedURLSpec, urlSpec));
+  }
+
+  try {
+    processURLSpecsAggregate.close();
+  } catch (error) {
+    niceShowAggregate(error);
+    logWarn`There were errors loading the optional URL specs you`;
+    logWarn`selected using ${'--urls'}. Since they might misfunction,`;
+    logWarn`debug the errors or remove the failing ones from ${'--urls'}.`;
+
+    Object.assign(stepStatusSummary.loadURLFiles, {
+      status: STATUS_FATAL_ERROR,
+      annotation: `see log for details`,
+      timeEnd: Date.now(),
+      memory: process.memoryUsage(),
+    });
+
+    return false;
+  }
+
+  if (showURLSpec) {
+    if (!paragraph) console.log('');
+
+    logInfo`Here's the final URL spec, via ${'--show-url-spec'}:`
+    console.log(urlSpec);
+    console.log('');
+
+    paragraph = true;
+  }
+
+  Object.assign(stepStatusSummary.loadURLFiles, {
+    status: STATUS_DONE_CLEAN,
+    timeEnd: Date.now(),
+    memory: process.memoryUsage(),
+  });
+
+  if (!getOrigin(urlSpec.thumb.prefix)) {
+    Object.assign(stepStatusSummary.loadOnlineThumbnailCache, {
+      status: STATUS_NOT_APPLICABLE,
+      annotation: `using offline thumbs`,
+    });
+  }
+
+  if (getOrigin(urlSpec.media.prefix)) {
+    Object.assign(stepStatusSummary.preloadFileSizes, {
+      status: STATUS_NOT_APPLICABLE,
+      annotation: `using online media`,
+    });
+  } else {
+    Object.assign(stepStatusSummary.loadOnlineFileSizeCache, {
+      status: STATUS_NOT_APPLICABLE,
+      annotation: `using offline media`,
+    });
+  }
+
+  applyLocalizedWithBaseDirectory(urlSpec);
+
+  const urls = generateURLs(urlSpec);
+
+  if (stepStatusSummary.loadOnlineThumbnailCache.status === STATUS_NOT_STARTED) loadOnlineThumbnailCache: {
+    Object.assign(stepStatusSummary.loadOnlineThumbnailCache, {
+      status: STATUS_STARTED_NOT_DONE,
+      timeStart: Date.now(),
+    });
+
+    let onlineThumbsCache = null;
+
+    const cacheFile = path.join(wikiCachePath, 'online-thumbnail-cache.json');
+
+    let readError = null;
+    let writeError = null;
+
+    if (!cliOptions['refresh-online-thumbs']) {
+      try {
+        onlineThumbsCache = JSON.parse(await readFile(cacheFile));
+      } catch (caughtError) {
+        readError = caughtError;
+      }
+    }
+
+    if (onlineThumbsCache) obliterateLocalCopy: {
+      if (!onlineThumbsCache._urlPrefix) {
+        // Well, it doesn't even count.
+        onlineThumbsCache = null;
+        break obliterateLocalCopy;
+      }
+
+      if (onlineThumbsCache._urlPrefix !== urlSpec.thumb.prefix) {
+        logInfo`Local copy of online thumbs cache is for a different prefix.`;
+        logInfo`It'll be downloaded and replaced, for reuse next time.`;
+        paragraph = false;
+
+        onlineThumbsCache = null;
+        break obliterateLocalCopy;
+      }
+
+      let stats;
+      try {
+        stats = await stat(cacheFile);
+      } catch {
+        logInfo`Unable to get the stats of local copy of online thumbs cache...`;
+        logInfo`This is really weird, since we *were* able to read it...`;
+        logInfo`We're just going to try writing to it and download fresh!`;
+        paragraph = false;
+
+        onlineThumbsCache = null;
+        break obliterateLocalCopy;
+      }
+
+      const delta = Date.now() - stats.mtimeMs;
+      const minute = 60 * 1000;
+      const delay = 60 * minute;
+
+      const whenst = duration => `~${Math.ceil(duration / minute)} min`;
+
+      if (delta < delay) {
+        logInfo`Online thumbs cache was downloaded recently, skipping for this build.`;
+        logInfo`Next scheduled is in ${whenst(delay - delta)}, or by using ${'--refresh-online-thumbs'}.`;
+        paragraph = false;
+
+        Object.assign(stepStatusSummary.loadOnlineThumbnailCache, {
+          status: STATUS_DONE_CLEAN,
+          annotation: `reusing local copy, earlier than scheduled`,
+          timeEnd: Date.now(),
+          memory: process.memoryUsage(),
+        });
+
+        thumbsCache = onlineThumbsCache;
+
+        break loadOnlineThumbnailCache;
+      } else {
+        logInfo`Online thumbs cache hasn't been downloaded for a little while.`;
+        logInfo`It'll be downloaded this build, then again in ${whenst(delay)}.`;
+        onlineThumbsCache = null;
+        paragraph = false;
+      }
+    }
+
+    try {
+      await writeFile(cacheFile, stringifyCache(onlineThumbsCache));
+    } catch (caughtError) {
+      writeError = caughtError;
+    }
+
+    if (readError && writeError && readError.code !== 'ENOENT') {
+      console.error(readError);
+      logWarn`Wasn't able to read the local copy of the`;
+      logWarn`online thumbs cache file...`;
+      console.error(writeError);
+      logWarn`...or write to it, either.`;
+      logWarn`The online thumbs cache will be downloaded`;
+      logWarn`for every build until you investigate this path:`;
+      logWarn`${cacheFile}`;
+      paragraph = false;
+    } else if (readError && readError.code === 'ENOENT' && !writeError) {
+      logInfo`No local copy of online thumbs cache.`;
+      logInfo`It'll be downloaded this time and reused next time.`;
+      paragraph = false;
+    } else if (readError && readError.code === 'ENOENT' && writeError) {
+      console.error(writeError);
+      logWarn`Doesn't look like we can write a local copy of`;
+      logWarn`the offline thumbs cache, at this path:`;
+      logWarn`${cacheFile}`;
+      logWarn`The online thumbs cache will be downloaded`;
+      logWarn`for every build until you investigate that.`;
+      paragraph = false;
+    }
+
+    const url = new URL(urlSpec.thumb.prefix);
+    url.pathname = path.posix.join(url.pathname, 'thumbnail-cache.json');
+
+    try {
+      onlineThumbsCache = await fetch(url).then(res => res.json());
+    } catch (error) {
+      console.error(error);
+      logWarn`There was an error downloading the online thumbnail cache.`;
+      logWarn`The wiki will act as though no thumbs are available at all.`;
+      paragraph = false;
+
+      Object.assign(stepStatusSummary.loadOnlineThumbnailCache, {
+        status: STATUS_HAS_WARNINGS,
+        annotation: `failed to download`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+
+      onlineThumbsCache = {};
+      thumbsCache = {};
+
+      break loadOnlineThumbnailCache;
+    }
+
+    onlineThumbsCache._urlPrefix = urlSpec.thumb.prefix;
+
+    thumbsCache = onlineThumbsCache;
+
+    if (onlineThumbsCache && !writeError) {
+      try {
+        await writeFile(cacheFile, stringifyCache(onlineThumbsCache));
+      } catch (error) {
+        console.error(error);
+        logWarn`There was an error saving a local copy of the`;
+        logWarn`online thumbnail cache. It'll be fetched again`;
+        logWarn`next time.`;
+        paragraph = false;
+
+        Object.assign(stepStatusSummary.loadOnlineThumbnailCache, {
+          status: STATUS_HAS_WARNINGS,
+          annotation: `failed to download`,
+          timeEnd: Date.now(),
+          memory: process.memoryUsage(),
+        });
+
+        break loadOnlineThumbnailCache;
+      }
+    }
+
+    Object.assign(stepStatusSummary.loadOnlineThumbnailCache, {
+      status: STATUS_DONE_CLEAN,
+      timeStart: Date.now(),
+      timeEnd: Date.now(),
+      memory: process.memoryUsage(),
+    });
+  }
+
   const languageReloading =
     stepStatusSummary.watchLanguageFiles.status === STATUS_NOT_STARTED;
 
@@ -1802,6 +2443,7 @@ async function main() {
       status: STATUS_FATAL_ERROR,
       annotation: `see log for details`,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     return false;
@@ -1815,6 +2457,7 @@ async function main() {
   Object.assign(stepStatusSummary.loadInternalDefaultLanguage, {
     status: STATUS_DONE_CLEAN,
     timeEnd: Date.now(),
+    memory: process.memoryUsage(),
   });
 
   let customLanguageWatchers;
@@ -1894,6 +2537,7 @@ async function main() {
             status: STATUS_FATAL_ERROR,
             annotation: `see log for details`,
             timeEnd: Date.now(),
+            memory: process.memoryUsage(),
           });
 
           errorLoadingCustomLanguages = true;
@@ -1925,6 +2569,7 @@ async function main() {
       Object.assign(stepStatusSummary.watchLanguageFiles, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } else {
       languages = {};
@@ -1948,11 +2593,13 @@ async function main() {
           status: STATUS_FATAL_ERROR,
           annotation: `see log for details`,
           timeEnd: Date.now(),
+          memory: process.memoryUsage(),
         });
       } else {
         Object.assign(stepStatusSummary.loadLanguageFiles, {
           status: STATUS_DONE_CLEAN,
           timeEnd: Date.now(),
+          memory: process.memoryUsage(),
         });
       }
     }
@@ -1990,6 +2637,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         annotation: `wiki specifies default language whose file is not available`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -2083,6 +2731,7 @@ async function main() {
     status: STATUS_DONE_CLEAN,
     annotation: finalDefaultLanguageAnnotation,
     timeEnd: Date.now(),
+    memory: process.memoryUsage(),
   });
 
   let missingImagePaths;
@@ -2105,85 +2754,225 @@ async function main() {
       Object.assign(stepStatusSummary.verifyImagePaths, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } else if (empty(missingImagePaths)) {
       Object.assign(stepStatusSummary.verifyImagePaths, {
         status: STATUS_HAS_WARNINGS,
         annotation: `misplaced images detected`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } else if (empty(misplacedImagePaths)) {
       Object.assign(stepStatusSummary.verifyImagePaths, {
         status: STATUS_HAS_WARNINGS,
         annotation: `missing images detected`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } else {
       Object.assign(stepStatusSummary.verifyImagePaths, {
         status: STATUS_HAS_WARNINGS,
         annotation: `missing and misplaced images detected`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     }
   }
 
-  let getSizeOfAdditionalFile;
-  let getSizeOfImagePath;
+  let getSizeOfMediaFile = () => null;
+
+  const fileSizePreloader =
+    new FileSizePreloader({
+      prefix: mediaPath,
+    });
+
+  if (stepStatusSummary.loadOnlineFileSizeCache.status === STATUS_NOT_STARTED) loadOnlineFileSizeCache: {
+    Object.assign(stepStatusSummary.loadOnlineFileSizeCache, {
+      status: STATUS_STARTED_NOT_DONE,
+      timeStart: Date.now(),
+    });
+
+    let onlineFileSizeCache = null;
+
+    const makeFileSizeCacheAvailable = () => {
+      fileSizePreloader.loadFromCache(onlineFileSizeCache);
+
+      getSizeOfMediaFile = p =>
+        fileSizePreloader.getSizeOfPath(
+          path.resolve(
+            mediaPath,
+            decodeURIComponent(p).split('/').join(path.sep)));
+    };
+
+    const cacheFile = path.join(wikiCachePath, 'online-file-size-cache.json');
+
+    let readError = null;
+    let writeError = null;
+
+    if (!cliOptions['refresh-online-file-sizes']) {
+      try {
+        onlineFileSizeCache = JSON.parse(await readFile(cacheFile));
+      } catch (caughtError) {
+        readError = caughtError;
+      }
+    }
+
+    if (onlineFileSizeCache) obliterateLocalCopy: {
+      if (!onlineFileSizeCache._urlPrefix) {
+        // Well, it doesn't even count.
+        onlineFileSizeCache = null;
+        break obliterateLocalCopy;
+      }
+
+      if (onlineFileSizeCache._urlPrefix !== urlSpec.media.prefix) {
+        logInfo`Local copy of online file size cache is for a different prefix.`;
+        logInfo`It'll be downloaded and replaced, for reuse next time.`;
+        paragraph = false;
+
+        onlineFileSizeCache = null;
+        break obliterateLocalCopy;
+      }
+
+      let stats;
+      try {
+        stats = await stat(cacheFile);
+      } catch {
+        logInfo`Unable to get the stats of local copy of online file size cache...`;
+        logInfo`This is really weird, since we *were* able to read it...`;
+        logInfo`We're just going to try writing to it and download fresh!`;
+        paragraph = false;
+
+        onlineFileSizeCache = null;
+        break obliterateLocalCopy;
+      }
+
+      const delta = Date.now() - stats.mtimeMs;
+      const minute = 60 * 1000;
+      const delay = 60 * minute;
+
+      const whenst = duration => `~${Math.ceil(duration / minute)} min`;
+
+      if (delta < delay) {
+        logInfo`Online file size cache was downloaded recently, skipping for this build.`;
+        logInfo`Next scheduled is in ${whenst(delay - delta)}, or by using ${'--refresh-online-file-sizes'}.`;
+        paragraph = false;
+
+        Object.assign(stepStatusSummary.loadOnlineFileSizeCache, {
+          status: STATUS_DONE_CLEAN,
+          annotation: `reusing local copy, earlier than scheduled`,
+          timeEnd: Date.now(),
+          memory: process.memoryUsage(),
+        });
 
-  if (stepStatusSummary.preloadFileSizes.status === STATUS_NOT_APPLICABLE) {
-    getSizeOfAdditionalFile = () => null;
-    getSizeOfImagePath = () => null;
-  } else if (stepStatusSummary.preloadFileSizes.status === STATUS_NOT_STARTED) {
+        delete onlineFileSizeCache._urlPrefix;
+
+        makeFileSizeCacheAvailable();
+
+        break loadOnlineFileSizeCache;
+      } else {
+        logInfo`Online file size hasn't been downloaded for a little while.`;
+        logInfo`It'll be downloaded this build, then again in ${whenst(delay)}.`;
+        onlineFileSizeCache = null;
+        paragraph = false;
+      }
+    }
+
+    try {
+      await writeFile(cacheFile, stringifyCache(onlineFileSizeCache));
+    } catch (caughtError) {
+      writeError = caughtError;
+    }
+
+    if (readError && writeError && readError.code !== 'ENOENT') {
+      console.error(readError);
+      logWarn`Wasn't able to read the local copy of the`;
+      logWarn`online file size cache file...`;
+      console.error(writeError);
+      logWarn`...or write to it, either.`;
+      logWarn`The online file size cache will be downloaded`;
+      logWarn`for every build until you investigate this path:`;
+      logWarn`${cacheFile}`;
+      paragraph = false;
+    } else if (readError && readError.code === 'ENOENT' && !writeError) {
+      logInfo`No local copy of online file size cache.`;
+      logInfo`It'll be downloaded this time and reused next time.`;
+      paragraph = false;
+    } else if (readError && readError.code === 'ENOENT' && writeError) {
+      console.error(writeError);
+      logWarn`Doesn't look like we can write a local copy of`;
+      logWarn`the offline file size cache, at this path:`;
+      logWarn`${cacheFile}`;
+      logWarn`The online file size cache will be downloaded`;
+      logWarn`for every build until you investigate that.`;
+      paragraph = false;
+    }
+
+    const url = new URL(urlSpec.media.prefix);
+    url.pathname = path.posix.join(url.pathname, 'file-size-cache.json');
+
+    try {
+      onlineFileSizeCache = await fetch(url).then(res => res.json());
+    } catch (error) {
+      console.error(error);
+      logWarn`There was an error downloading the online file size cache.`;
+      logWarn`The wiki will act as though no file sizes are available at all.`;
+      paragraph = false;
+
+      Object.assign(stepStatusSummary.loadOnlineFileSizeCache, {
+        status: STATUS_HAS_WARNINGS,
+        annotation: `failed to download`,
+        timeEnd: Date.now(),
+        memory: process.memoryUsage(),
+      });
+
+      break loadOnlineFileSizeCache;
+    }
+
+    makeFileSizeCacheAvailable();
+
+    onlineFileSizeCache._urlPrefix = urlSpec.media.prefix;
+
+    if (onlineFileSizeCache && !writeError) {
+      try {
+        await writeFile(cacheFile, stringifyCache(onlineFileSizeCache));
+      } catch (error) {
+        console.error(error);
+        logWarn`There was an error saving a local copy of the`;
+        logWarn`online file size cache. It'll be fetched again`;
+        logWarn`next time.`;
+        paragraph = false;
+
+        Object.assign(stepStatusSummary.loadOnlineFileSizeCache, {
+          status: STATUS_HAS_WARNINGS,
+          annotation: `failed to download`,
+          timeEnd: Date.now(),
+          memory: process.memoryUsage(),
+        });
+
+        break loadOnlineFileSizeCache;
+      }
+    }
+
+    Object.assign(stepStatusSummary.loadOnlineFileSizeCache, {
+      status: STATUS_DONE_CLEAN,
+      timeStart: Date.now(),
+      timeEnd: Date.now(),
+      memory: process.memoryUsage(),
+    });
+  }
+
+  if (stepStatusSummary.preloadFileSizes.status === STATUS_NOT_STARTED) {
     Object.assign(stepStatusSummary.preloadFileSizes, {
       status: STATUS_STARTED_NOT_DONE,
       timeStart: Date.now(),
     });
 
-    const fileSizePreloader = new FileSizePreloader();
-
-    // File sizes of additional files need to be precalculated before we can
-    // actually reference 'em in site building, so get those loading right
-    // away. We actually need to keep track of two things here - the on-device
-    // file paths we're actually reading, and the corresponding on-site media
-    // paths that will be exposed in site build code. We'll build a mapping
-    // function between them so that when site code requests a site path,
-    // it'll get the size of the file at the corresponding device path.
-    const additionalFilePaths = [
-      ...wikiData.albumData.flatMap((album) =>
-        [
-          ...(album.additionalFiles ?? []),
-          ...album.tracks.flatMap((track) => [
-            ...(track.additionalFiles ?? []),
-            ...(track.sheetMusicFiles ?? []),
-            ...(track.midiProjectFiles ?? []),
-          ]),
-        ]
-          .flatMap((fileGroup) => fileGroup.files ?? [])
-          .map((file) => ({
-            device: path.join(
-              mediaPath,
-              urls
-                .from('media.root')
-                .toDevice('media.albumAdditionalFile', album.directory, file)
-            ),
-            media: urls
-              .from('media.root')
-              .to('media.albumAdditionalFile', album.directory, file),
-          }))
-      ),
-    ];
-
-    // Same dealio for images. Since just about any image can be embedded and
-    // we can't super easily know which ones are referenced at runtime, just
-    // cheat and get file sizes for all images under media. (This includes
-    // additional files which are images.)
-    const imageFilePaths =
+    const mediaFilePaths =
       await traverse(mediaPath, {
         pathStyle: 'device',
         filterDir: dir => dir !== '.git',
-        filterFile: file =>
-          ['.png', '.gif', '.jpg'].includes(path.extname(file)) &&
-          !isThumb(file),
+        filterFile: file => !isThumb(file),
       }).then(files => files
           .map(file => ({
             device: file,
@@ -2193,28 +2982,19 @@ async function main() {
                 .to('media.path', path.relative(mediaPath, file).split(path.sep).join('/')),
           })));
 
-    const getSizeOfMediaFileHelper = paths => (mediaPath) => {
-      const pair = paths.find(({media}) => media === mediaPath);
+    getSizeOfMediaFile = mediaPath => {
+      const pair = mediaFilePaths.find(({media}) => media === mediaPath);
       if (!pair) return null;
       return fileSizePreloader.getSizeOfPath(pair.device);
     };
 
-    getSizeOfAdditionalFile = getSizeOfMediaFileHelper(additionalFilePaths);
-    getSizeOfImagePath = getSizeOfMediaFileHelper(imageFilePaths);
-
-    logInfo`Preloading filesizes for ${additionalFilePaths.length} additional files...`;
-
-    fileSizePreloader.loadPaths(...additionalFilePaths.map((path) => path.device));
-    await fileSizePreloader.waitUntilDoneLoading();
-
-    logInfo`Preloading filesizes for ${imageFilePaths.length} full-resolution images...`;
-    paragraph = false;
+    logInfo`Preloading file sizes for ${mediaFilePaths.length} media files...`;
 
-    fileSizePreloader.loadPaths(...imageFilePaths.map((path) => path.device));
+    fileSizePreloader.loadPaths(...mediaFilePaths.map(path => path.device));
     await fileSizePreloader.waitUntilDoneLoading();
 
     if (fileSizePreloader.hasErrored) {
-      logWarn`Some media files couldn't be read for preloading filesizes.`;
+      logWarn`Some media files couldn't be read for preloading file sizes.`;
       logWarn`This means the wiki won't display file sizes for these files.`;
       logWarn`Investigate missing or unreadable files to get that fixed!`;
 
@@ -2222,16 +3002,50 @@ async function main() {
         status: STATUS_HAS_WARNINGS,
         annotation: `see log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } else {
-      logInfo`Done preloading filesizes without any errors - nice!`;
+      logInfo`Done preloading file sizes without any errors - nice!`;
       paragraph = false;
 
       Object.assign(stepStatusSummary.preloadFileSizes, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     }
+
+    // TODO: kinda jank that this is out of band of any particular step,
+    // even though it's operationally a follow-up to preloadFileSizes
+
+    let oopsCache = false;
+    saveFileSizeCache: {
+      let cache;
+      try {
+        cache = fileSizePreloader.saveAsCache();
+      } catch (error) {
+        console.error(error);
+        logWarn`Couldn't compute file size preloader's cache.`;
+        oopsCache = true;
+        break saveFileSizeCache;
+      }
+
+      const cacheFile = path.join(mediaPath, 'file-size-cache.json');
+
+      try {
+        await writeFile(cacheFile, stringifyCache(cache));
+      } catch (error) {
+        console.error(error);
+        logWarn`Couldn't save preloaded file sizes to a cache file:`;
+        logWarn`${cacheFile}`;
+        oopsCache = true;
+      }
+    }
+
+    if (oopsCache) {
+      logWarn`This won't affect the build, but this build should not be used`;
+      logWarn`as a model for another build accessing its media files online.`;
+    }
   }
 
   if (stepStatusSummary.buildSearchIndex.status === STATUS_NOT_STARTED) {
@@ -2254,6 +3068,7 @@ async function main() {
       Object.assign(stepStatusSummary.buildSearchIndex, {
         status: STATUS_DONE_CLEAN,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     } catch (error) {
       if (!paragraph) console.log('');
@@ -2271,6 +3086,7 @@ async function main() {
         status: STATUS_HAS_WARNINGS,
         annotation: `see log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
     }
   }
@@ -2318,6 +3134,7 @@ async function main() {
         status: STATUS_FATAL_ERROR,
         message: `JavaScript error - view log for details`,
         timeEnd: Date.now(),
+        memory: process.memoryUsage(),
       });
 
       return false;
@@ -2329,6 +3146,7 @@ async function main() {
     Object.assign(stepStatusSummary.identifyWebRoutes, {
       status: STATUS_DONE_CLEAN,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
   }
 
@@ -2382,29 +3200,36 @@ async function main() {
   logInfo`Passing control over to build mode: ${selectedBuildModeFlag}`;
   console.log('');
 
+  const universalUtilities = {
+    getSizeOfMediaFile,
+
+    defaultLanguage: finalDefaultLanguage,
+    developersComment,
+    languages,
+    missingImagePaths,
+    thumbsCache,
+    urlSpec,
+    urls,
+    wikiData,
+  };
+
   try {
     buildModeResult = await selectedBuildMode.go({
       cliOptions,
+      queueSize,
+
+      universalUtilities,
+      ...universalUtilities,
+
       dataPath,
       mediaPath,
       mediaCachePath,
       wikiCachePath,
-      queueSize,
       srcRootPath: __dirname,
 
-      defaultLanguage: finalDefaultLanguage,
-      languages,
-      missingImagePaths,
-      thumbsCache,
-      urls,
-      urlSpec,
       webRoutes: preparedWebRoutes,
-      wikiData,
 
       closeLanguageWatchers,
-      developersComment,
-      getSizeOfAdditionalFile,
-      getSizeOfImagePath,
       niceShowAggregate,
     });
   } catch (error) {
@@ -2417,6 +3242,7 @@ async function main() {
       status: STATUS_FATAL_ERROR,
       message: `javascript error - view log for details`,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     return false;
@@ -2427,6 +3253,7 @@ async function main() {
       status: STATUS_HAS_WARNINGS,
       annotation: `may not have completed - view log for details`,
       timeEnd: Date.now(),
+      memory: process.memoryUsage(),
     });
 
     return false;
@@ -2435,6 +3262,7 @@ async function main() {
   Object.assign(stepStatusSummary.performBuild, {
     status: STATUS_DONE_CLEAN,
     timeEnd: Date.now(),
+    memory: process.memoryUsage(),
   });
 
   return true;
@@ -2445,126 +3273,67 @@ async function main() {
 if (true || isMain(import.meta.url) || path.basename(process.argv[1]) === 'hsmusic') {
   (async () => {
     let result;
+    let numRestarts = 0;
 
     const totalTimeStart = Date.now();
 
-    try {
-      result = await main();
-    } catch (error) {
-      if (error instanceof AggregateError) {
-        showAggregate(error);
-      } else if (error.cause) {
-        console.error(error);
-        showAggregate(error);
-      } else {
-        console.error(error);
-      }
-    }
-
-    const totalTimeEnd = Date.now();
-
-    const formatDuration = timeDelta => {
-      const seconds = timeDelta / 1000;
-
-      if (seconds > 90) {
-        const modSeconds = Math.floor(seconds % 60);
-        const minutes = Math.floor(seconds - seconds % 60) / 60;
-        return `${minutes}m${modSeconds}s`;
-      }
-
-      if (seconds < 0.1) {
-        return 'instant';
+    while (true) {
+      try {
+        result = await main();
+      } catch (error) {
+        if (error instanceof AggregateError) {
+          showAggregate(error);
+        } else if (error.cause) {
+          console.error(error);
+          showAggregate(error);
+        } else {
+          console.error(error);
+        }
       }
 
-      const precision = (seconds > 1 ? 3 : 2);
-      return `${seconds.toPrecision(precision)}s`;
-    };
-
-    if (showStepStatusSummary) {
-      const totalDuration = formatDuration(totalTimeEnd - totalTimeStart);
-
-      console.error(colors.bright(`Step summary:`));
-
-      const longestNameLength =
-        Math.max(...
-          Object.values(stepStatusSummary)
-            .map(({name}) => name.length));
-
-      const stepsNotClean =
-        Object.values(stepStatusSummary)
-          .map(({status}) =>
-            status === STATUS_HAS_WARNINGS ||
-            status === STATUS_FATAL_ERROR ||
-            status === STATUS_STARTED_NOT_DONE);
-
-      const anyStepsNotClean =
-        stepsNotClean.includes(true);
-
-      const stepDetails = Object.values(stepStatusSummary);
-
-      const stepDurations =
-        stepDetails.map(({status, timeStart, timeEnd}) => {
-          if (
-            status === STATUS_NOT_APPLICABLE ||
-            status === STATUS_NOT_STARTED ||
-            status === STATUS_STARTED_NOT_DONE
-          ) {
-            return '-';
-          }
+      if (result === 'restart') {
+        console.log('');
 
-          if (typeof timeStart !== 'number' || typeof timeEnd !== 'number') {
-            return 'unknown';
+        if (shouldShowStepStatusSummary) {
+          if (numRestarts >= 1) {
+            console.error(colors.bright(`Step summary since latest restart:`));
+          } else {
+            console.error(colors.bright(`Step summary before restart:`));
           }
 
-          return formatDuration(timeEnd - timeStart);
-        });
-
-      const longestDurationLength =
-        Math.max(...stepDurations.map(duration => duration.length));
-
-      for (let index = 0; index < stepDetails.length; index++) {
-        const {name, status, annotation} = stepDetails[index];
-        const duration = stepDurations[index];
-
-        let message =
-          (stepsNotClean[index]
-            ? `!! `
-            : ` - `);
-
-        message += `(${duration})`.padStart(longestDurationLength + 2, ' ');
-        message += ` `;
-        message += `${name}: `.padEnd(longestNameLength + 4, '.');
-        message += ` `;
-        message += status;
-
-        if (annotation) {
-          message += ` (${annotation})`;
+          showStepStatusSummary();
+          console.log('');
         }
 
-        switch (status) {
-          case STATUS_DONE_CLEAN:
-            console.error(colors.green(message));
-            break;
-
-          case STATUS_NOT_STARTED:
-          case STATUS_NOT_APPLICABLE:
-            console.error(colors.dim(message));
-            break;
+        if (numRestarts > 5) {
+          logError`A restart was cued, but we've restarted a bunch already.`;
+          logError`Exiting because this is probably a bug!`;
+          console.log('');
+          break;
+        } else {
+          console.log('');
+          logInfo`A restart was cued. This is probably normal, and required`;
+          logInfo`to load updated data files. Restarting automatically now!`;
+          console.log('');
+          numRestarts++;
+        }
+      } else {
+        break;
+      }
+    }
 
-          case STATUS_HAS_WARNINGS:
-          case STATUS_STARTED_NOT_DONE:
-            console.error(colors.yellow(message));
-            break;
+    if (shouldShowStepStatusSummary)  {
+      if (numRestarts >= 1) {
+        console.error(colors.bright(`Step summary after final restart:`));
+      } else {
+        console.error(colors.bright(`Step summary:`));
+      }
 
-          case STATUS_FATAL_ERROR:
-            console.error(colors.red(message));
-            break;
+      const {anyStepsNotClean} =
+        showStepStatusSummary();
 
-          default:
-            console.error(message);
-            break;
-        }
-      }
+      const totalTimeEnd = Date.now();
+      const totalDuration = formatDuration(totalTimeEnd - totalTimeStart);
 
       console.error(colors.bright(`Done in ${totalDuration}.`));
 
@@ -2589,8 +3358,124 @@ if (true || isMain(import.meta.url) || path.basename(process.argv[1]) === 'hsmus
     }
 
     decorateTime.displayTime();
-    CacheableObject.showInvalidAccesses();
 
     process.exit(0);
   })();
 }
+
+function formatDuration(timeDelta) {
+  const seconds = timeDelta / 1000;
+
+  if (seconds > 90) {
+    const modSeconds = Math.floor(seconds % 60);
+    const minutes = Math.floor(seconds - seconds % 60) / 60;
+    return `${minutes}m${modSeconds}s`;
+  }
+
+  if (seconds < 0.1) {
+    return 'instant';
+  }
+
+  const precision = (seconds > 1 ? 3 : 2);
+  return `${seconds.toPrecision(precision)}s`;
+}
+
+function showStepStatusSummary() {
+  const longestNameLength =
+    Math.max(...
+      Object.values(stepStatusSummary)
+        .map(({name}) => name.length));
+
+  const stepsNotClean =
+    Object.values(stepStatusSummary)
+      .map(({status}) =>
+        status === STATUS_HAS_WARNINGS ||
+        status === STATUS_FATAL_ERROR ||
+        status === STATUS_STARTED_NOT_DONE);
+
+  const anyStepsNotClean =
+    stepsNotClean.includes(true);
+
+  const stepDetails = Object.values(stepStatusSummary);
+
+  const stepDurations =
+    stepDetails.map(({status, timeStart, timeEnd}) => {
+      if (
+        status === STATUS_NOT_APPLICABLE ||
+        status === STATUS_NOT_STARTED ||
+        status === STATUS_STARTED_NOT_DONE
+      ) {
+        return '-';
+      }
+
+      if (typeof timeStart !== 'number' || typeof timeEnd !== 'number') {
+        return 'unknown';
+      }
+
+      return formatDuration(timeEnd - timeStart);
+    });
+
+  const longestDurationLength =
+    Math.max(...stepDurations.map(duration => duration.length));
+
+  const stepMemories =
+    stepDetails.map(({memory}) =>
+      (memory
+        ? Math.round(memory["heapUsed"] / 1024 / 1024) + 'MB'
+        : '-'));
+
+  const longestMemoryLength =
+    Math.max(...stepMemories.map(memory => memory.length));
+
+  for (let index = 0; index < stepDetails.length; index++) {
+    const {name, status, annotation} = stepDetails[index];
+    const duration = stepDurations[index];
+    const memory = stepMemories[index];
+
+    let message =
+      (stepsNotClean[index]
+        ? `!! `
+        : ` - `);
+
+    message += `(${duration} `.padStart(longestDurationLength + 2, ' ');
+
+    if (shouldShowStepMemoryInSummary) {
+      message += ` ${memory})`.padStart(longestMemoryLength + 2, ' ');
+    }
+
+    message += ` `;
+    message += `${name}: `.padEnd(longestNameLength + 4, '.');
+    message += ` `;
+    message += status;
+
+    if (annotation) {
+      message += ` (${annotation})`;
+    }
+
+    switch (status) {
+      case STATUS_DONE_CLEAN:
+        console.error(colors.green(message));
+        break;
+
+      case STATUS_NOT_STARTED:
+      case STATUS_NOT_APPLICABLE:
+        console.error(colors.dim(message));
+        break;
+
+      case STATUS_HAS_WARNINGS:
+      case STATUS_STARTED_NOT_DONE:
+        console.error(colors.yellow(message));
+        break;
+
+      case STATUS_FATAL_ERROR:
+        console.error(colors.red(message));
+        break;
+
+      default:
+        console.error(message);
+        break;
+    }
+  }
+
+  return {anyStepsNotClean};
+}