From 21428931e905c898c8272765539255bcb802c19e Mon Sep 17 00:00:00 2001 From: Mike Primm Date: Sun, 13 Jan 2013 03:49:07 -0800 Subject: [PATCH] Compressed Nibble Arrays Implement 'lightening' of NibbleArrays - only allocate buffers when non-trivial value Saving from 40-45% of memory use by chunk section data. Finish up NibbleArray lightening work - use for Snapshots, reduce copies Fix nibble handling with NBT - arrays aren't copied by NBTByteArray diff --git a/src/main/java/net/minecraft/server/ChunkRegionLoader.java b/src/main/java/net/minecraft/server/ChunkRegionLoader.java index 1e1499e..76b081a 100644 --- a/src/main/java/net/minecraft/server/ChunkRegionLoader.java +++ b/src/main/java/net/minecraft/server/ChunkRegionLoader.java @@ -225,15 +225,15 @@ public class ChunkRegionLoader implements IChunkLoader, IAsyncChunkSaver { nbttagcompound1.setByte("Y", (byte) (chunksection.getYPosition() >> 4 & 255)); nbttagcompound1.setByteArray("Blocks", chunksection.getIdArray()); if (chunksection.getExtendedIdArray() != null) { - nbttagcompound1.setByteArray("Add", chunksection.getExtendedIdArray().a); + nbttagcompound1.setByteArray("Add", chunksection.getExtendedIdArray().getValueArray()); // Spigot } - nbttagcompound1.setByteArray("Data", chunksection.getDataArray().a); - nbttagcompound1.setByteArray("BlockLight", chunksection.getEmittedLightArray().a); + nbttagcompound1.setByteArray("Data", chunksection.getDataArray().getValueArray()); // Spigot + nbttagcompound1.setByteArray("BlockLight", chunksection.getEmittedLightArray().getValueArray()); // Spigot if (flag) { - nbttagcompound1.setByteArray("SkyLight", chunksection.getSkyLightArray().a); + nbttagcompound1.setByteArray("SkyLight", chunksection.getSkyLightArray().getValueArray()); // Spigot } else { - nbttagcompound1.setByteArray("SkyLight", new byte[chunksection.getEmittedLightArray().a.length]); + nbttagcompound1.setByteArray("SkyLight", new byte[chunksection.getEmittedLightArray().getValueArray().length]); // Spigot } nbttaglist.add(nbttagcompound1); diff --git a/src/main/java/net/minecraft/server/ChunkSection.java b/src/main/java/net/minecraft/server/ChunkSection.java index a05efa0..360de1a 100644 --- a/src/main/java/net/minecraft/server/ChunkSection.java +++ b/src/main/java/net/minecraft/server/ChunkSection.java @@ -140,7 +140,8 @@ public class ChunkSection { } } } else { - byte[] ext = this.extBlockIds.a; + this.extBlockIds.forceToNonTrivialArray(); // Spigot + byte[] ext = this.extBlockIds.getValueArray(); for (int off = 0, off2 = 0; off < blkIds.length;) { byte extid = ext[off2]; int l = (blkIds[off] & 0xFF) | ((extid & 0xF) << 8); // Even data @@ -171,6 +172,12 @@ public class ChunkSection { off++; off2++; } + // Spigot start + this.extBlockIds.detectAndProcessTrivialArray(); + if (this.extBlockIds.isTrivialArray() && (this.extBlockIds.getTrivialArrayValue() == 0)) { + this.extBlockIds = null; + } + // Spigot end } this.nonEmptyBlockCount = cntNonEmpty; this.tickingBlockCount = cntTicking; @@ -224,12 +231,11 @@ public class ChunkSection { public void setExtendedIdArray(NibbleArray nibblearray) { // CraftBukkit start - Don't hang on to an empty nibble array boolean empty = true; - for (int i = 0; i < nibblearray.a.length; i++) { - if (nibblearray.a[i] != 0) { - empty = false; - break; - } + // Spigot start + if ((!nibblearray.isTrivialArray()) || (nibblearray.getTrivialArrayValue() != 0)) { + empty = false; } + // Spigot end if (empty) { return; @@ -253,11 +259,11 @@ public class ChunkSection { // CraftBukkit start - Validate array lengths private NibbleArray validateNibbleArray(NibbleArray nibbleArray) { - if (nibbleArray != null && nibbleArray.a.length < 2048) { - byte[] newArray = new byte[2048]; - System.arraycopy(nibbleArray.a, 0, newArray, 0, ((nibbleArray.a.length > 2048) ? 2048 : nibbleArray.a.length)); - nibbleArray = new NibbleArray(newArray, 4); + // Spigot start - fix for more awesome nibble arrays + if (nibbleArray != null && nibbleArray.getByteLength() < 2048) { + nibbleArray.resizeArray(2048); } + // Spigot end return nibbleArray; } diff --git a/src/main/java/net/minecraft/server/NibbleArray.java b/src/main/java/net/minecraft/server/NibbleArray.java index 5d75a54..c9bc20c 100644 --- a/src/main/java/net/minecraft/server/NibbleArray.java +++ b/src/main/java/net/minecraft/server/NibbleArray.java @@ -1,13 +1,117 @@ package net.minecraft.server; +import java.util.Arrays; // Spigot + public class NibbleArray { - public final byte[] a; + private byte[] a; // Spigot - remove final, make private (anyone directly accessing this is broken already) private final int b; private final int c; + // Spigot start + private byte trivialValue; + private byte trivialByte; + private int length; + private static final int LEN2K = 2048; // Universal length used right now - optimize around this + private static final byte[][] TrivLen2k; + + static { + TrivLen2k = new byte[16][]; + for (int i = 0; i < 16; i++) { + TrivLen2k[i] = new byte[LEN2K]; + Arrays.fill(TrivLen2k[i], (byte) (i | (i << 4))); + } + } + + // Try to convert array to trivial array + public void detectAndProcessTrivialArray() { + trivialValue = (byte) (a[0] & 0xF); + trivialByte = (byte) (trivialValue | (trivialValue << 4)); + for (int i = 0; i < a.length; i++) { + if (a[i] != trivialByte) return; + } + // All values matches, so array is trivial + this.length = a.length; + this.a = null; + } + + // Force array to non-trivial state + public void forceToNonTrivialArray() { + if (this.a == null) { + this.a = new byte[this.length]; + if (this.trivialByte != 0) { + Arrays.fill(this.a, this.trivialByte); + } + } + } + + // Test if array is in trivial state + public boolean isTrivialArray() { + return (this.a == null); + } + + // Get value of all elements (only valid if array is in trivial state) + public int getTrivialArrayValue() { + return this.trivialValue; + } + + // Get logical length of byte array for nibble data (whether trivial or non-trivial) + public int getByteLength() { + if (this.a == null) { + return this.length; + } else { + return this.a.length; + } + } + + // Return byte encoding of array (whether trivial or non-trivial) - returns read-only array if trivial (do not modify!) + public byte[] getValueArray() { + if (this.a != null) { + return this.a; + } else { + byte[] rslt; + + if (this.length == LEN2K) { // All current uses are 2k long, but be safe + rslt = TrivLen2k[this.trivialValue]; + } else { + rslt = new byte[this.length]; + if (this.trivialByte != 0) { + Arrays.fill(rslt, this.trivialByte); + } + } + return rslt; + } + } + + // Copy byte representation of array to given offset in given byte array + public int copyToByteArray(byte[] dest, int off) { + if (this.a == null) { + Arrays.fill(dest, off, off + this.length, this.trivialByte); + return off + this.length; + } else { + System.arraycopy(this.a, 0, dest, off, this.a.length); + return off + this.a.length; + } + } + + // Resize array to given byte length + public void resizeArray(int len) { + if (this.a == null) { + this.length = len; + } else if (this.a.length != len) { + byte[] newa = new byte[len]; + System.arraycopy(this.a, 0, newa, 0, ((this.a.length > len) ? len : this.a.length)); + this.a = newa; + } + } + // Spigot end public NibbleArray(int i, int j) { - this.a = new byte[i >> 1]; + // Spigot start + //this.a = new byte[i >> 1]; + this.a = null; // Start off as trivial value (all same zero value) + this.length = i >> 1; + this.trivialByte = this.trivialValue = 0; + // Spigot end this.b = j; this.c = j + 4; } @@ -16,9 +120,11 @@ public class NibbleArray { this.a = abyte; this.b = i; this.c = i + 4; + detectAndProcessTrivialArray(); // Spigot } public int a(int i, int j, int k) { + if (this.a == null) return this.trivialValue; // Spigot int l = j << this.c | k << this.b | i; int i1 = l >> 1; int j1 = l & 1; @@ -27,6 +133,18 @@ public class NibbleArray { } public void a(int i, int j, int k, int l) { + // Spigot start + if (this.a == null) { + if (l != this.trivialValue) { // Not same as trivial value, array no longer trivial + this.a = new byte[this.length]; + if (this.trivialByte != 0) { + Arrays.fill(this.a, this.trivialByte); + } + } else { + return; + } + } + // Spigot end int i1 = j << this.c | k << this.b | i; int j1 = i1 >> 1; int k1 = i1 & 1; diff --git a/src/main/java/net/minecraft/server/OldChunkLoader.java b/src/main/java/net/minecraft/server/OldChunkLoader.java index fcb9912..6ee28cc 100644 --- a/src/main/java/net/minecraft/server/OldChunkLoader.java +++ b/src/main/java/net/minecraft/server/OldChunkLoader.java @@ -94,9 +94,11 @@ public class OldChunkLoader { nbttagcompound1.setByte("Y", (byte) (k & 255)); nbttagcompound1.setByteArray("Blocks", abyte); - nbttagcompound1.setByteArray("Data", nibblearray.a); - nbttagcompound1.setByteArray("SkyLight", nibblearray1.a); - nbttagcompound1.setByteArray("BlockLight", nibblearray2.a); + // Spigot start - a -> getValueArray() accessor + nbttagcompound1.setByteArray("Data", nibblearray.getValueArray()); + nbttagcompound1.setByteArray("SkyLight", nibblearray1.getValueArray()); + nbttagcompound1.setByteArray("BlockLight", nibblearray2.getValueArray()); + // Spigot end nbttaglist.add(nbttagcompound1); } } diff --git a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java index b2c6ef4..55f5225 100644 --- a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java +++ b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java @@ -174,7 +174,18 @@ public class CraftChunk implements Chunk { } if (cs[i].getExtendedIdArray() != null) { /* If we've got extended IDs */ - byte[] extids = cs[i].getExtendedIdArray().a; + // Spigot start + if (cs[i].getExtendedIdArray().isTrivialArray()) { + int tval = cs[i].getExtendedIdArray().getTrivialArrayValue(); + if (tval != 0) { + tval = tval << 8; + for (int j = 0; j < 4096; j++) { + blockids[j] |= tval; + } + } + } else { + byte[] extids = cs[i].getExtendedIdArray().getValueArray(); + // Spigot end for (int j = 0; j < 2048; j++) { short b = (short) (extids[j] & 0xFF); @@ -186,21 +197,42 @@ public class CraftChunk implements Chunk { blockids[j<<1] |= (b & 0x0F) << 8; blockids[(j<<1)+1] |= (b & 0xF0) << 4; } + } // Spigot } sectionBlockIDs[i] = blockids; /* Get block data nibbles */ - sectionBlockData[i] = new byte[2048]; - System.arraycopy(cs[i].getDataArray().a, 0, sectionBlockData[i], 0, 2048); + // Spigot start + if (cs[i].getDataArray().isTrivialArray() && (cs[i].getDataArray().getTrivialArrayValue() == 0)) { + sectionBlockData[i] = emptyData; + } else { + sectionBlockData[i] = new byte[2048]; + cs[i].getDataArray().copyToByteArray(sectionBlockData[i], 0); + } if (cs[i].getSkyLightArray() == null) { sectionSkyLights[i] = emptyData; + } + else if (cs[i].getSkyLightArray().isTrivialArray()) { + if (cs[i].getSkyLightArray().getTrivialArrayValue() == 0) { + sectionSkyLights[i] = emptyData; + } else if (cs[i].getSkyLightArray().getTrivialArrayValue() == 15) { + sectionSkyLights[i] = emptySkyLight; + } else { + sectionSkyLights[i] = new byte[2048]; + cs[i].getSkyLightArray().copyToByteArray(sectionSkyLights[i], 0); + } } else { sectionSkyLights[i] = new byte[2048]; - System.arraycopy(cs[i].getSkyLightArray().a, 0, sectionSkyLights[i], 0, 2048); + cs[i].getSkyLightArray().copyToByteArray(sectionSkyLights[i], 0); + } + if (cs[i].getEmittedLightArray().isTrivialArray() && (cs[i].getEmittedLightArray().getTrivialArrayValue() == 0)) { + sectionEmitLights[i] = emptyData; + } else { + sectionEmitLights[i] = new byte[2048]; + cs[i].getEmittedLightArray().copyToByteArray(sectionEmitLights[i], 0); } - sectionEmitLights[i] = new byte[2048]; - System.arraycopy(cs[i].getEmittedLightArray().a, 0, sectionEmitLights[i], 0, 2048); + // Spigot end } } -- 1.8.3.2