Restore decompressedSize behaviour...

and add new method `getFrameContentSize` that will return also the error.

Author: luben

src/main/java/com/github/luben/zstd/Zstd.java

@@ -579,6 +579,28 @@ public static long decompressDirectByteBufferFastDict(ByteBuffer dst, int dstOff
     public static native int setRefMultipleDDicts(long stream, boolean useMultiple);
 
     /* Utility methods */
+    /**
+     * Return the original size of a compressed buffer (if known)
+     *
+     * @param src the compressed buffer
+     * @param srcPosition offset of the compressed data inside the src buffer
+     * @param srcSize length of the compressed data inside the src buffer
+     * @param magicless whether the buffer contains a magicless frame
+     * @return the number of bytes of the original buffer
+     *         0 if the original size is not known,
+     *         negative if there is an error decoding the frame header
+     */
+    public static long getFrameContentSize(byte[] src, int srcPosition, int srcSize, boolean magicless) {
+        if (srcPosition >= src.length) {
+            throw new ArrayIndexOutOfBoundsException(srcPosition);
+        }
+        if (srcPosition + srcSize > src.length) {
+            throw new ArrayIndexOutOfBoundsException(srcPosition + srcSize);
+        }
+        return getFrameContentSize0(src, srcPosition, srcSize, magicless);
+    }
+
+    private static native long getFrameContentSize0(byte[] src, int srcPosition, int srcSize, boolean magicless);
 
     /**
      * Return the original size of a compressed buffer (if known)
@@ -589,7 +611,10 @@ public static long decompressDirectByteBufferFastDict(ByteBuffer dst, int dstOff
      * @param magicless whether the buffer contains a magicless frame
      * @return the number of bytes of the original buffer
      *         0 if the original size is not known
+     * @deprecated
+     * Use `getFrameContentSize` that return also the errors
      */
+    @Deprecated
     public static long decompressedSize(byte[] src, int srcPosition, int srcSize, boolean magicless) {
         if (srcPosition >= src.length) {
             throw new ArrayIndexOutOfBoundsException(srcPosition);
@@ -602,6 +627,20 @@ public static long decompressedSize(byte[] src, int srcPosition, int srcSize, bo
 
     private static native long decompressedSize0(byte[] src, int srcPosition, int srcSize, boolean magicless);
 
+    /**
+     * Return the original size of a compressed buffer (if known)
+     *
+     * @param src the compressed buffer
+     * @param srcPosition offset of the compressed data inside the src buffer
+     * @param srcSize length of the compressed data inside the src buffer
+     * @return the number of bytes of the original buffer
+     *         0 if the original size is not known,
+     *         negative if there is an error decoding the frame header
+     */
+    public static long getFrameContentSize(byte[] src, int srcPosition, int srcSize) {
+        return getFrameContentSize(src, srcPosition, srcSize, false);
+    }
+
     /**
      * Return the original size of a compressed buffer (if known)
      *
@@ -610,30 +649,67 @@ public static long decompressedSize(byte[] src, int srcPosition, int srcSize, bo
      * @param srcSize length of the compressed data inside the src buffer
      * @return the number of bytes of the original buffer
      *         0 if the original size is not known
+     * @deprecated
+     * Use `getFrameContentSize` that return also the errors
      */
+    @Deprecated
     public static long decompressedSize(byte[] src, int srcPosition, int srcSize) {
         return decompressedSize(src, srcPosition, srcSize, false);
     }
 
+    /**
+     * Return the original size of a compressed buffer (if known)
+     *
+     * @param src the compressed buffer
+     * @param srcPosition offset of the compressed data inside the src buffer
+     * @param srcSize length of the compressed data inside the src buffer
+     * @return the number of bytes of the original buffer
+     *         0 if the original size is not known,
+     *         negative if there is an error decoding the frame header
+     */
+    public static long getFrameContentSize(byte[] src, int srcPosition) {
+        return getFrameContentSize(src, srcPosition, src.length - srcPosition);
+    }
+
     /**
      * Return the original size of a compressed buffer (if known)
      *
      * @param src the compressed buffer
      * @param srcPosition offset of the compressed data inside the src buffer
      * @return the number of bytes of the original buffer
      *         0 if the original size is not known
+     * @deprecated
+     * Use `getFrameContentSize` that return also the errors
      */
+    @Deprecated
     public static long decompressedSize(byte[] src, int srcPosition) {
         return decompressedSize(src, srcPosition, src.length - srcPosition);
     }
 
+    /**
+     * Return the original size of a compressed buffer (if known)
+     *
+     * @param src the compressed buffer
+     * @param srcPosition offset of the compressed data inside the src buffer
+     * @param srcSize length of the compressed data inside the src buffer
+     * @return the number of bytes of the original buffer
+     *         0 if the original size is not known,
+     *         negative if there is an error decoding the frame header
+     */
+    public static long getFrameContentSize(byte[] src) {
+        return getFrameContentSize(src, 0);
+    }
+
     /**
      * Return the original size of a compressed buffer (if known)
      *
      * @param src the compressed buffer
      * @return the number of bytes of the original buffer
      *         0 if the original size is not known
+     * @deprecated
+     * Use `getFrameContentSize` that return also the errors
      */
+    @Deprecated
     public static long decompressedSize(byte[] src) {
         return decompressedSize(src, 0);
     };
@@ -647,9 +723,25 @@ public static long decompressedSize(byte[] src) {
      * @param magicless whether the buffer contains a magicless frame
      * @return the number of bytes of the original buffer
      *         0 if the original size is not known
+     * @deprecated
+     * Use `getDirectByteBuferFrameContentSize` that return also the errors
      */
+    @Deprecated
     public static native long decompressedDirectByteBufferSize(ByteBuffer src, int srcPosition, int srcSize, boolean magicless);
 
+    /**
+     * Return the original size of a compressed buffer (if known)
+     *
+     * @param src the compressed buffer
+     * @param srcPosition offset of the compressed data inside the src buffer
+     * @param srcSize length of the compressed data inside the src buffe
+     * @param magicless whether the buffer contains a magicless frame
+     * @return the number of bytes of the original buffer
+     *         0 if the original size is not known
+     *         negative if there is an error decoding the frame header
+     */
+    public static native long getDirectByteBuferFrameContentSize(ByteBuffer src, int srcPosition, int srcSize, boolean magicless);
+
     /**
      * Return the original size of a compressed buffer (if known)
      *
@@ -658,11 +750,28 @@ public static long decompressedSize(byte[] src) {
      * @param srcSize length of the compressed data inside the src buffe
      * @return the number of bytes of the original buffer
      *         0 if the original size is not known
+     * @deprecated
+     * Use `getDirectByteBuferFrameContentSize` that return also the errors
      */
+    @Deprecated
     public static long decompressedDirectByteBufferSize(ByteBuffer src, int srcPosition, int srcSize) {
         return decompressedDirectByteBufferSize(src, srcPosition, srcSize, false);
     }
 
+    /**
+     * Return the original size of a compressed buffer (if known)
+     *
+     * @param src the compressed buffer
+     * @param srcPosition offset of the compressed data inside the src buffer
+     * @param srcSize length of the compressed data inside the src buffe
+     * @return the number of bytes of the original buffer
+     *         0 if the original size is not known
+     *         negative if there is an error decoding the frame header
+     */
+    public static long getDirectByteBuferFrameContentSize(ByteBuffer src, int srcPosition, int srcSize) {
+        return getDirectByteBuferFrameContentSize(src, srcPosition, srcSize, false);
+    }
+
     /**
      * Maximum size of the compressed data
      *

src/main/native/jni_zstd.c

@@ -74,9 +74,26 @@ JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_Zstd_decompressedSize0
     if (src_buff == NULL) goto E1;
     size = JNI_ZSTD_decompressedSize(((char *) src_buff) + offset, (size_t) limit, magicless);
     (*env)->ReleasePrimitiveArrayCritical(env, src, src_buff, JNI_ABORT);
+    if (size <= 0) return 0;
 E1: return size;
 }
 
+/*
+ * Class:     com_github_luben_zstd_Zstd
+ * Method:    getFrameContentSize0
+ * Signature: ([B)JII
+ */
+JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_Zstd_getFrameContentSize0
+  (JNIEnv *env, jclass obj, jbyteArray src, jint offset, jint limit, jboolean magicless) {
+    size_t size = -ZSTD_error_memory_allocation;
+    void *src_buff = (*env)->GetPrimitiveArrayCritical(env, src, NULL);
+    if (src_buff == NULL) goto E1;
+    size = JNI_ZSTD_decompressedSize(((char *) src_buff) + offset, (size_t) limit, magicless);
+    (*env)->ReleasePrimitiveArrayCritical(env, src, src_buff, JNI_ABORT);
+E1: return size;
+}
+
+
 /*
  * Class:     com_github_luben_zstd_Zstd
  * Method:    getDictIdFromFrame
@@ -155,6 +172,23 @@ JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_Zstd_decompressedDirectByteBu
 E1: return size;
 }
 
+/*
+ * Class:     com_github_luben_zstd_Zstd
+ * Method:    getDirectByteBufferFrameContentSize
+ * Signature: (Ljava/nio/ByteBuffer;II)J
+ */
+JNIEXPORT jlong JNICALL Java_com_github_luben_zstd_Zstd_getDirectByteBufferFrameContentSize
+  (JNIEnv *env, jclass obj, jobject src_buf, jint src_offset, jint src_size, jboolean magicless) {
+    size_t size = -ZSTD_error_memory_allocation;
+    jsize src_cap = (*env)->GetDirectBufferCapacity(env, src_buf);
+    if (src_offset + src_size > src_cap) return -ZSTD_error_GENERIC;
+    char *src_buf_ptr = (char*)(*env)->GetDirectBufferAddress(env, src_buf);
+    if (src_buf_ptr == NULL) goto E1;
+    size = JNI_ZSTD_decompressedSize(src_buf_ptr + src_offset, (size_t) src_size, magicless);
+    if (size <= 0) return 0;
+E1: return size;
+}
+
 /*
  * Class:     com_github_luben_zstd_Zstd
  * Method:    compressBound