R3944Realms/ModernFix-fix
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Improve ZipPackIndex

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embeddedt 2026-05-28 22:20:28 -04:00
parent 33851c1cb6
commit fb9dcf77c6
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1 changed files with 102 additions and 53 deletions
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src/main/java/org/embeddedt/modernfix/resources/ZipPackIndex.java
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@ -1,5 +1,8 @@
package org.embeddedt.modernfix.resources;
import it.unimi.dsi.fastutil.ints.IntArrayList;
import it.unimi.dsi.fastutil.ints.IntList;
import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.server.packs.PackResources;
import net.minecraft.server.packs.PackType;
@ -46,7 +49,7 @@ public class ZipPackIndex {
private static final int CD_OFF_EXTRA_LENGTH = 30;
private static final int CD_OFF_COMMENT_LENGTH = 32;
private static final int[] EMPTY_OFFSETS = new int[0];
private static final IntList EMPTY_OFFSETS = IntList.of();
// -------------------------------------------------------------------------
// DirNode
@ -54,14 +57,17 @@ public class ZipPackIndex {
static final class DirNode {
Map<String, DirNode> childDirs;
int[] fileChildOffsets; // offsets into cdBuffer for each direct file child
IntList fileChildOffsets; // offsets into cdBuffer for each direct file child
DirNode() {
childDirs = new HashMap<>();
childDirs = new Object2ObjectOpenHashMap<>();
fileChildOffsets = EMPTY_OFFSETS;
}
void freeze() {
if (fileChildOffsets instanceof IntArrayList arrayList) {
arrayList.trim();
}
childDirs = childDirs.isEmpty() ? Map.of() : Map.copyOf(childDirs);
for (DirNode child : childDirs.values()) {
child.freeze();
@ -75,6 +81,8 @@ public class ZipPackIndex {
/** Central directory buffer (memory-mapped or heap-allocated fallback). May be null for empty/invalid zips. */
private final ByteBuffer cdBuffer;
/** Top-level directories tracked by the index. */
private final Set<String> trackedTopLevelDirs;
/** Root of the directory tree, always non-null (may be empty but frozen). */
private final DirNode root;
@ -90,6 +98,11 @@ public class ZipPackIndex {
*/
public ZipPackIndex(Path zipPath) throws IOException {
this.cdBuffer = readCentralDirectory(zipPath);
// Computed here (not statically) so that any loader-injected PackType values
// registered after class-load are included.
Set<String> packTypeDirs = new HashSet<>();
for (PackType type : PackType.values()) packTypeDirs.add(type.getDirectory());
this.trackedTopLevelDirs = Set.copyOf(packTypeDirs);
this.root = buildTree();
}
@ -159,70 +172,79 @@ public class ZipPackIndex {
}
private DirNode buildTree() throws IOException {
var cdBuffer = this.cdBuffer;
DirNode treeRoot = new DirNode();
if (cdBuffer == null) {
treeRoot.freeze();
return treeRoot;
}
// Computed here (not statically) so that any loader-injected PackType values
// registered after class-load are included.
Set<String> packTypeDirs = new HashSet<>();
for (PackType type : PackType.values()) packTypeDirs.add(type.getDirectory());
// Accumulate file offsets per DirNode before compacting to int[]
IdentityHashMap<DirNode, List<Integer>> fileOffsets = new IdentityHashMap<>();
int pos = 0;
int limit = cdBuffer.limit();
while (pos + CD_ENTRY_HEADER_SIZE <= limit) {
if (cdBuffer.getInt(pos) != CD_ENTRY_SIGNATURE) break;
int fileNameLen = Short.toUnsignedInt(cdBuffer.getShort(pos + CD_OFF_FILENAME_LENGTH));
int extraLen = Short.toUnsignedInt(cdBuffer.getShort(pos + CD_OFF_EXTRA_LENGTH));
int commentLen = Short.toUnsignedInt(cdBuffer.getShort(pos + CD_OFF_COMMENT_LENGTH));
int recordLen = CD_ENTRY_HEADER_SIZE + fileNameLen + extraLen + commentLen;
if (pos + recordLen > limit) {
throw new IOException("Truncated central directory");
}
byte[] nameBytes = new byte[fileNameLen];
cdBuffer.get(pos + CD_ENTRY_HEADER_SIZE, nameBytes);
String name = new String(nameBytes, StandardCharsets.UTF_8);
boolean isDirectory = name.endsWith("/");
if (isDirectory) name = name.substring(0, name.length() - 1);
if (!name.isEmpty()) {
String[] parts = name.split("/");
if (!packTypeDirs.contains(parts[0])) {
pos += recordLen;
continue;
}
DirNode current = treeRoot;
int dirDepth = isDirectory ? parts.length : parts.length - 1;
for (int i = 0; i < dirDepth; i++) {
current = current.childDirs.computeIfAbsent(parts[i], k -> new DirNode());
}
if (!isDirectory) {
fileOffsets.computeIfAbsent(current, k -> new ArrayList<>()).add(pos);
}
}
pos += recordLen;
pos += indexCdEntry(pos, limit, treeRoot, cdBuffer);
}
// Compact to int[] arrays
fileOffsets.forEach((node, offsets) -> {
int[] arr = new int[offsets.size()];
for (int i = 0; i < arr.length; i++) arr[i] = offsets.get(i);
node.fileChildOffsets = arr;
});
treeRoot.freeze();
return treeRoot;
}
/**
* Parses the CD entry at {@code pos}, inserts it into the tree, and returns the
* number of bytes to advance {@code pos} (i.e. the full record length).
*/
private int indexCdEntry(int pos, int limit,
DirNode treeRoot,
ByteBuffer cdBuffer) throws IOException {
int fileNameLen = Short.toUnsignedInt(cdBuffer.getShort(pos + CD_OFF_FILENAME_LENGTH));
int extraLen = Short.toUnsignedInt(cdBuffer.getShort(pos + CD_OFF_EXTRA_LENGTH));
int commentLen = Short.toUnsignedInt(cdBuffer.getShort(pos + CD_OFF_COMMENT_LENGTH));
int recordLen = CD_ENTRY_HEADER_SIZE + fileNameLen + extraLen + commentLen;
if (pos + recordLen > limit) {
throw new IOException("Truncated central directory");
}
byte[] nameBytes = new byte[fileNameLen];
cdBuffer.get(pos + CD_ENTRY_HEADER_SIZE, nameBytes);
DirNode current = treeRoot;
boolean tracked = false;
boolean skipped = false;
int segStart = 0;
for (int i = 0; i < fileNameLen; i++) {
if (nameBytes[i] == '/') {
int segLen = i - segStart;
if (segLen > 0) {
String segment = new String(nameBytes, segStart, segLen, StandardCharsets.UTF_8);
if (!tracked) {
if (!trackedTopLevelDirs.contains(segment)) { skipped = true; break; }
tracked = true;
}
DirNode next = current.childDirs.get(segment);
//noinspection Java8MapApi
if (next == null) {
current.childDirs.put(segment, next = new DirNode());
}
current = next;
}
segStart = i + 1;
}
}
// A remaining non-empty segment after the last '/' is a file basename.
if (!skipped && tracked && segStart < fileNameLen) {
if (current.fileChildOffsets == EMPTY_OFFSETS) {
current.fileChildOffsets = new IntArrayList();
}
current.fileChildOffsets.add(pos);
}
return recordLen;
}
// -------------------------------------------------------------------------
// CD buffer reads — absolute-position gets are thread-safe on Java 13+
// -------------------------------------------------------------------------
@ -246,6 +268,10 @@ public class ZipPackIndex {
// Public API
// -------------------------------------------------------------------------
public Set<String> getTrackedTopLevelDirs() {
return this.trackedTopLevelDirs;
}
/**
* Returns all namespaces present under the given pack type directory.
*
@ -264,6 +290,28 @@ public class ZipPackIndex {
return result;
}
public boolean hasResource(String... paths) {
var node = this.root;
for (int i = 0; i < paths.length - 1; i++) {
var path = paths[i];
if (path.isEmpty()) {
continue;
}
node = node.childDirs.get(path);
if (node == null) {
return false;
}
}
String basename = paths[paths.length - 1];
var offsets = node.fileChildOffsets;
for (int i = 0; i < offsets.size(); i++) {
if (basename.equals(readBasename(offsets.getInt(i)))) {
return true;
}
}
return false;
}
/**
* Enumerate all resources under {@code type/namespace/path/} and deliver them
* to {@code output}.
@ -310,8 +358,9 @@ public class ZipPackIndex {
ZipFile zipFile, String namespace,
PackResources.ResourceOutput output) {
// Emit direct file children of this node
for (int cdOffset : node.fileChildOffsets) {
String basename = readBasename(cdOffset);
var offsets = node.fileChildOffsets;
for (int i = 0; i < offsets.size(); i++) {
String basename = readBasename(offsets.getInt(i));
String rlPathFull = rlSubPath + basename;
ResourceLocation rl = ResourceLocation.tryBuild(namespace, rlPathFull);
if (rl != null) {