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Merged
luben merged 3 commits into from
Mar 8, 2025
+167 −11
Merged

Support decompression from byte array to ByteBuffer and vice-versa #351

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0a32c8e
Support decompression from byte array to ByteBuffer and vice-versa
charlesconnell Mar 3, 2025
b623376
Fix lock acquisition
charlesconnell Mar 8, 2025
67dd181
indentation
charlesconnell Mar 8, 2025
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18 changes: 18 additions & 0 deletions src/main/java/com/github/luben/zstd/Zstd.java
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Original file line number Diff line number Diff line change
Expand Up @@ -418,6 +418,15 @@ public static long decompress(byte[] dst, byte[] src) {
}
}

public static int decompress(byte[] dst, ByteBuffer srcBuf) {
ZstdDecompressCtx ctx = new ZstdDecompressCtx();
try {
return ctx.decompress(dst, srcBuf);
} finally {
ctx.close();
}
}

/**
* Decompresses buffer 'src' into buffer 'dst'.
*
Expand Down Expand Up @@ -1343,6 +1352,15 @@ public static int decompress(ByteBuffer dstBuf, ByteBuffer srcBuf) {
}
}

public static int decompress(ByteBuffer dstBuf, byte[] src) {
ZstdDecompressCtx ctx = new ZstdDecompressCtx();
try {
return ctx.decompress(dstBuf, src);
} finally {
ctx.close();
}
}

/**
* Decompress data
*
Expand Down
76 changes: 76 additions & 0 deletions src/main/java/com/github/luben/zstd/ZstdDecompressCtx.java
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Original file line number Diff line number Diff line change
Expand Up @@ -234,6 +234,60 @@ public int decompressByteArray(byte[] dstBuff, int dstOffset, int dstSize, byte[

private static native long decompressByteArray0(long nativePtr, byte[] dst, int dstOffset, int dstSize, byte[] src, int srcOffset, int srcSize);

public int decompressByteArrayToDirectByteBuffer(ByteBuffer dstBuff, int dstOffset, int dstSize, byte[] srcBuff, int srcOffset, int srcSize) {
if (!dstBuff.isDirect()) {
throw new IllegalArgumentException("dstBuff must be a direct buffer");
}

Objects.checkFromIndexSize(srcOffset, srcSize, srcBuff.length);
Objects.checkFromIndexSize(dstOffset, dstSize, dstBuff.limit());

ensureOpen();
acquireSharedLock();

try {
long size = decompressByteArrayToDirectByteBuffer0(nativePtr, dstBuff, dstOffset, dstSize, srcBuff, srcOffset, srcSize);
if (Zstd.isError(size)) {
throw new ZstdException(size);
}
if (size > Integer.MAX_VALUE) {
throw new ZstdException(Zstd.errGeneric(), "Output size is greater than MAX_INT");
}
return (int) size;
} finally {
releaseSharedLock();
}
}

private static native long decompressByteArrayToDirectByteBuffer0(long nativePtr, ByteBuffer dst, int dstOffset, int dstSize, byte[] src, int srcOffset, int srcSize);

public int decompressDirectByteBufferToByteArray(byte[] dstBuff, int dstOffset, int dstSize, ByteBuffer srcBuff, int srcOffset, int srcSize) {
if (!srcBuff.isDirect()) {
throw new IllegalArgumentException("srcBuff must be a direct buffer");
}

Objects.checkFromIndexSize(srcOffset, srcSize, srcBuff.limit());
Objects.checkFromIndexSize(dstOffset, dstSize, dstBuff.length);

ensureOpen();
acquireSharedLock();

try {
long size = decompressDirectByteBufferToByteArray0(nativePtr, dstBuff, dstOffset, dstSize, srcBuff, srcOffset, srcSize);
if (Zstd.isError(size)) {
throw new ZstdException(size);
}
if (size > Integer.MAX_VALUE) {
throw new ZstdException(Zstd.errGeneric(), "Output size is greater than MAX_INT");
}
return (int) size;
} finally {
releaseSharedLock();
}
}

private static native long decompressDirectByteBufferToByteArray0(long nativePtr, byte[] dst, int dstOffset, int dstSize, ByteBuffer src, int srcOffset, int srcSize);

/* Covenience methods */

/**
Expand Down Expand Up @@ -267,6 +321,28 @@ public int decompress(ByteBuffer dstBuf, ByteBuffer srcBuf) throws ZstdException
return size;
}

public int decompress(ByteBuffer dstBuf, byte[] src) throws ZstdException {
int size = decompressByteArrayToDirectByteBuffer(dstBuf, // decompress into dstBuf
dstBuf.position(), // write decompressed data at offset position()
dstBuf.limit() - dstBuf.position(), // write no more than limit() - position()
src, // read compressed data from src
0,
src.length);
dstBuf.position(dstBuf.position() + size);
return size;
}

public int decompress(byte[] dst, ByteBuffer srcBuf) throws ZstdException {
int size = decompressDirectByteBufferToByteArray(dst, // decompress into dst
0,
dst.length,
srcBuf, // read compressed data from srcBuf
srcBuf.position(), // read starting at offset position()
srcBuf.limit() - srcBuf.position()); // read no more than limit() - position()
srcBuf.position(srcBuf.limit());
return size;
}

public ByteBuffer decompress(ByteBuffer srcBuf, int originalSize) throws ZstdException {
ByteBuffer dstBuf = ByteBuffer.allocateDirect(originalSize);
int size = decompressDirectByteBuffer(dstBuf, 0, originalSize, srcBuf, srcBuf.position(), srcBuf.limit() - srcBuf.position());
Expand Down
66 changes: 66 additions & 0 deletions src/main/native/jni_fast_zstd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -689,3 +689,69 @@ JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_ZstdDecompressCtx_decompressB
E2: (*env)->ReleasePrimitiveArrayCritical(env, dst, dst_buff, 0);
E1: return size;
}

/*
* Class: com_github_luben_zstd_ZstdDecompressCtx
* Method: decompressByteArrayToDirectByteBuffer0
* Signature: (Ljava/nio/ByteBuffer;II[BII)I
*/
JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_ZstdDecompressCtx_decompressByteArrayToDirectByteBuffer0
(JNIEnv *env, jclass jclazz, jlong ptr, jobject dst, jint dst_offset, jint dst_size, jbyteArray src, jint src_offset, jint src_size) {
size_t size = -ZSTD_error_memory_allocation;

if (NULL == dst) return -ZSTD_error_dstSize_tooSmall;
if (NULL == src) return -ZSTD_error_srcSize_wrong;
if (0 > dst_offset) return -ZSTD_error_dstSize_tooSmall;
if (0 > src_offset) return -ZSTD_error_srcSize_wrong;
if (0 > src_size) return -ZSTD_error_srcSize_wrong;

if (src_offset + src_size > (*env)->GetArrayLength(env, src)) return -ZSTD_error_srcSize_wrong;
jsize dst_cap = (*env)->GetDirectBufferCapacity(env, dst);
if (dst_offset + dst_size > dst_cap) return -ZSTD_error_dstSize_tooSmall;

ZSTD_DCtx* dctx = (ZSTD_DCtx*)(intptr_t)ptr;

char *dst_buff = (char*)(*env)->GetDirectBufferAddress(env, dst);
if (dst_buff == NULL) return -ZSTD_error_memory_allocation;
void *src_buff = (*env)->GetPrimitiveArrayCritical(env, src, NULL);
if (src_buff == NULL) goto E1;

ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only);
size = ZSTD_decompressDCtx(dctx, ((char *)dst_buff) + dst_offset, (size_t) dst_size, ((char *)src_buff) + src_offset, (size_t) src_size);

(*env)->ReleasePrimitiveArrayCritical(env, src, src_buff, JNI_ABORT);
E1: return size;
}

/*
* Class: com_github_luben_zstd_ZstdDecompressCtx
* Method: decompressDirectByteBufferToByteArray0
* Signature: ([BIILjava/nio/ByteBuffer;II)I
*/
JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_ZstdDecompressCtx_decompressDirectByteBufferToByteArray0
(JNIEnv *env, jclass jclazz, jlong ptr, jbyteArray dst, jint dst_offset, jint dst_size, jobject src, jint src_offset, jint src_size) {
size_t size = -ZSTD_error_memory_allocation;

if (NULL == dst) return -ZSTD_error_dstSize_tooSmall;
if (NULL == src) return -ZSTD_error_srcSize_wrong;
if (0 > dst_offset) return -ZSTD_error_dstSize_tooSmall;
if (0 > src_offset) return -ZSTD_error_srcSize_wrong;
if (0 > src_size) return -ZSTD_error_srcSize_wrong;

if (dst_offset + dst_size > (*env)->GetArrayLength(env, dst)) return -ZSTD_error_dstSize_tooSmall;
jsize src_cap = (*env)->GetDirectBufferCapacity(env, src);
if (src_offset + src_size > src_cap) return -ZSTD_error_srcSize_wrong;

ZSTD_DCtx* dctx = (ZSTD_DCtx*)(intptr_t)ptr;

char *src_buff = (char*)(*env)->GetDirectBufferAddress(env, src);
if (src_buff == NULL) return -ZSTD_error_memory_allocation;
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@luben luben Mar 7, 2025

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this will leave the dst_buff behind critical lock that is never going to be released. I suggest adding E2 on the line before E1 and jump there.

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@luben luben Mar 7, 2025

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another option is to swap the GetPrimitiveArrayCritical and GetDirectBufferAddress sections

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@charlesconnell charlesconnell Mar 8, 2025

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That's fixed, thank you.

void *dst_buff = (*env)->GetPrimitiveArrayCritical(env, dst, NULL);
if (dst_buff == NULL) goto E1;

ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only);
size = ZSTD_decompressDCtx(dctx, ((char *)dst_buff) + dst_offset, (size_t) dst_size, ((char *)src_buff) + src_offset, (size_t) src_size);

(*env)->ReleasePrimitiveArrayCritical(env, dst, dst_buff, 0);
E1: return size;
}
18 changes: 7 additions & 11 deletions src/test/scala/Zstd.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -86,13 +86,10 @@ class ZstdSpec extends AnyFlatSpec with ScalaCheckPropertyChecks {
val size = input.length
val compressed = Zstd.compress(input, level)

val compressedBuffer = ByteBuffer.allocateDirect(Zstd.compressBound(size.toLong).toInt)
compressedBuffer.put(compressed)
compressedBuffer.limit(compressedBuffer.position())
compressedBuffer.flip()

val decompressedBuffer = Zstd.decompress(compressedBuffer, size)
val decompressed = new Array[Byte](size)
val decompressedBuffer = ByteBuffer.allocateDirect(size)
val decompressedSize = Zstd.decompress(decompressedBuffer, compressed);
val decompressed = new Array[Byte](decompressedSize)
decompressedBuffer.flip();
decompressedBuffer.get(decompressed)
input.toSeq == decompressed.toSeq
}
Expand All @@ -104,11 +101,10 @@ class ZstdSpec extends AnyFlatSpec with ScalaCheckPropertyChecks {
val inputBuffer = ByteBuffer.allocateDirect(size)
inputBuffer.put(input)
inputBuffer.flip()
val compressedBuffer = Zstd.compress(inputBuffer, level)
val compressed = new Array[Byte](compressedBuffer.limit() - compressedBuffer.position())
compressedBuffer.get(compressed)
val compressedBuffer = Zstd.compress(inputBuffer, level)

val decompressed = Zstd.decompress(compressed, size)
val decompressed = new Array[Byte](size)
Zstd.decompress(decompressed, compressedBuffer)
input.toSeq == decompressed.toSeq
}
}
Expand Down
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