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Hopefully fix the algorithm for good
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@lukastaegert
lukastaegert committed Dec 16, 2022
1 parent 04339f8 commit 1ee5d10
Showing 1 changed file with 76 additions and 57 deletions.
133 changes: 76 additions & 57 deletions src/utils/chunkAssignment.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -209,7 +209,6 @@ interface ChunkDescription {
signature: string;
size: number;
transitiveDependencies: Set<ChunkDescription>;
transitiveDependentChunks: Set<ChunkDescription>;
}

type ChunkPartition = {
Expand Down Expand Up @@ -285,42 +284,49 @@ small ${`${chunkPartition.small.pure.size}`.padEnd(5, ' ')} ${chunkPartition.sma
Unoptimized chunks contain ${getNumberOfCycles(chunkPartition)} cycles.
`);

console.log(
`Trying to find merge targets for ${
chunkPartition.small.sideEffect.size
} chunks smaller than ${prettyBytes(minChunkSize)} with side effects...`
);
mergeChunks(
chunkPartition.small.sideEffect,
[chunkPartition.small.pure, chunkPartition.big.pure],
minChunkSize,
chunkPartition
);
console.log(
`${chunkPartition.small.sideEffect.size} chunks smaller than ${prettyBytes(
minChunkSize
)} with side effects remaining.\nGenerated chunks contain ${getNumberOfCycles(
chunkPartition
)} cycles.\n`
);
const chunkAliases = new Map<ChunkDescription, ChunkDescription>();
if (chunkPartition.small.sideEffect.size > 0) {
console.log(
`Trying to find merge targets for ${
chunkPartition.small.sideEffect.size
} chunks smaller than ${prettyBytes(minChunkSize)} with side effects...`
);
mergeChunks(
chunkPartition.small.sideEffect,
[chunkPartition.small.pure, chunkPartition.big.pure],
minChunkSize,
chunkPartition,
chunkAliases
);
console.log(
`${chunkPartition.small.sideEffect.size} chunks smaller than ${prettyBytes(
minChunkSize
)} with side effects remaining.\nGenerated chunks contain ${getNumberOfCycles(
chunkPartition
)} cycles.\n`
);
}

console.log(
`Trying to find merge targets for ${
chunkPartition.small.pure.size
} pure chunks smaller than ${prettyBytes(minChunkSize)}...`
);
mergeChunks(
chunkPartition.small.pure,
[chunkPartition.small.pure, chunkPartition.big.sideEffect, chunkPartition.big.pure],
minChunkSize,
chunkPartition
);
if (chunkPartition.small.pure.size > 0) {
console.log(
`Trying to find merge targets for ${
chunkPartition.small.pure.size
} pure chunks smaller than ${prettyBytes(minChunkSize)}...`
);
mergeChunks(
chunkPartition.small.pure,
[chunkPartition.small.pure, chunkPartition.big.sideEffect, chunkPartition.big.pure],
minChunkSize,
chunkPartition,
chunkAliases
);

console.log(
`${chunkPartition.small.pure.size} pure chunks smaller than ${prettyBytes(
minChunkSize
)} remaining.\nGenerated chunks contain ${getNumberOfCycles(chunkPartition)} cycles.\n`
);
console.log(
`${chunkPartition.small.pure.size} pure chunks smaller than ${prettyBytes(
minChunkSize
)} remaining.\nGenerated chunks contain ${getNumberOfCycles(chunkPartition)} cycles.\n`
);
}
timeEnd('optimize chunks', 3);
const result = [
...chunkPartition.small.sideEffect,
Expand Down Expand Up @@ -438,7 +444,6 @@ function sortChunksAndAddDependencies(
const transitiveDependency = chunkByModule.get(module)!;
if (transitiveDependency !== chunk) {
transitiveDependencies.add(transitiveDependency);
transitiveDependency.transitiveDependentChunks.add(chunk);
for (const dependency of module.getDependenciesToBeIncluded()) {
if (!(dependency instanceof ExternalModule)) {
transitiveDependencyModules.add(dependency);
Expand All @@ -461,9 +466,11 @@ function mergeChunks(
chunksToBeMerged: Set<ChunkDescription>,
targetChunks: Set<ChunkDescription>[],
minChunkSize: number,
chunkPartition: ChunkPartition
chunkPartition: ChunkPartition,
chunkAliases: Map<ChunkDescription, ChunkDescription>
) {
for (const mergedChunk of chunksToBeMerged) {
replaceAliasedDependencies(mergedChunk, chunkAliases);
let closestChunk: ChunkDescription | null = null;
let closestChunkDistance = Infinity;
const { signature, modules, pure, size } = mergedChunk;
Expand All @@ -473,7 +480,7 @@ function mergeChunks(
const distance = pure
? getSignatureDistance(signature, targetChunk.signature, !targetChunk.pure)
: getSignatureDistance(targetChunk.signature, signature, true);
if (distance < closestChunkDistance && isValidMerge(mergedChunk, targetChunk)) {
if (distance < closestChunkDistance && isValidMerge(mergedChunk, targetChunk, chunkAliases)) {
if (distance === 1) {
closestChunk = targetChunk;
break;
Expand All @@ -483,47 +490,59 @@ function mergeChunks(
}
}
if (closestChunk) {
chunkAliases.set(mergedChunk, closestChunk);
chunksToBeMerged.delete(mergedChunk);
getChunksInPartition(closestChunk, minChunkSize, chunkPartition).delete(closestChunk);
closestChunk.modules.push(...modules);
closestChunk.size += size;
closestChunk.pure &&= pure;
closestChunk.signature = mergeSignatures(signature, closestChunk.signature);
const { dependencies, transitiveDependencies, transitiveDependentChunks } = closestChunk;
const { dependencies, transitiveDependencies } = closestChunk;
for (const dependency of mergedChunk.dependencies) {
dependencies.add(dependency);
}
for (const dependency of mergedChunk.transitiveDependencies) {
transitiveDependencies.add(dependency);
dependency.transitiveDependentChunks.delete(mergedChunk);
dependency.transitiveDependentChunks.add(closestChunk);
}
for (const dependentChunk of mergedChunk.transitiveDependentChunks) {
transitiveDependentChunks.add(dependentChunk);
if (dependentChunk.dependencies.has(mergedChunk)) {
dependentChunk.dependencies.delete(mergedChunk);
dependentChunk.dependencies.add(closestChunk);
}
dependentChunk.transitiveDependencies.delete(mergedChunk);
dependentChunk.transitiveDependencies.add(closestChunk);
}
dependencies.delete(closestChunk);
dependencies.delete(mergedChunk);
transitiveDependencies.delete(closestChunk);
transitiveDependentChunks.delete(closestChunk);
transitiveDependencies.delete(mergedChunk);
getChunksInPartition(closestChunk, minChunkSize, chunkPartition).add(closestChunk);
}
}
}

function replaceAliasedDependencies(
chunk: ChunkDescription,
chunkAliases: Map<ChunkDescription, ChunkDescription>
) {
for (const [alias, aliased] of chunkAliases) {
if (chunk.dependencies.has(alias)) {
chunk.dependencies.delete(alias);
chunk.dependencies.add(aliased);
}
if (chunk.transitiveDependencies.has(alias)) {
chunk.transitiveDependencies.delete(alias);
chunk.transitiveDependencies.add(aliased);
}
}
}

// Merging will not produce cycles if
// - no chunk is a transitive dependency of the other, or
// - none of the direct non-merged dependencies of a chunk have the other
// - none of the direct non-merged dependencies of a chunk have the other
// chunk as a transitive dependency
function isValidMerge(mergedChunk: ChunkDescription, targetChunk: ChunkDescription) {
return !(
hasTransitiveDependency(mergedChunk, targetChunk) ||
hasTransitiveDependency(targetChunk, mergedChunk)
);
function isValidMerge(
mergedChunk: ChunkDescription,
targetChunk: ChunkDescription,
chunkAliases: Map<ChunkDescription, ChunkDescription>
) {
if (hasTransitiveDependency(mergedChunk, targetChunk)) {
return false;
}
replaceAliasedDependencies(targetChunk, chunkAliases);
return !hasTransitiveDependency(targetChunk, mergedChunk);
}

function hasTransitiveDependency(
Expand Down

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