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#include "rrdpush.h"
#ifdef ENABLE_COMPRESSION
#include "lz4.h"
#define STREAM_COMPRESSION_MSG "STREAM_COMPRESSION"
#define LZ4_MAX_MSG_SIZE 0x4000
#define LZ4_STREAM_BUFFER_SIZE (0x10000 + LZ4_MAX_MSG_SIZE)
#define SIGNATURE ((uint32_t)('z' | 0x80) | (0x80 << 8) | (0x80 << 16) | ('\n' << 24))
#define SIGNATURE_MASK ((uint32_t)0xff | (0x80 << 8) | (0x80 << 16) | (0xff << 24))
#define SIGNATURE_SIZE 4
/*
* LZ4 streaming API compressor specific data
*/
struct compressor_data {
LZ4_stream_t *stream;
char *stream_buffer;
size_t stream_buffer_pos;
};
/*
* Reset compressor state for a new stream
*/
static void lz4_compressor_reset(struct compressor_state *state)
{
if (state->data) {
if (state->data->stream) {
LZ4_resetStream_fast(state->data->stream);
info("%s: Compressor Reset", STREAM_COMPRESSION_MSG);
}
state->data->stream_buffer_pos = 0;
}
}
/*
* Destroy compressor state and all related data
*/
static void lz4_compressor_destroy(struct compressor_state **state)
{
if (state && *state) {
struct compressor_state *s = *state;
if (s->data) {
if (s->data->stream)
LZ4_freeStream(s->data->stream);
freez(s->data->stream_buffer);
freez(s->data);
}
freez(s->buffer);
freez(s);
*state = NULL;
debug(D_STREAM, "%s: Compressor Destroyed.", STREAM_COMPRESSION_MSG);
}
}
/*
* Compress the given block of data
* Compressed data will remain in the internal buffer until the next invocation
* Return the size of compressed data block as result and the pointer to internal buffer using the last argument
* or 0 in case of error
*/
static size_t lz4_compressor_compress(struct compressor_state *state, const char *data, size_t size, char **out)
{
if (!state || !size || !out)
return 0;
if (size > LZ4_MAX_MSG_SIZE) {
error("%s: Compression Failed - Message size %lu above compression buffer limit: %d", STREAM_COMPRESSION_MSG, size, LZ4_MAX_MSG_SIZE);
return 0;
}
size_t max_dst_size = LZ4_COMPRESSBOUND(size);
size_t data_size = max_dst_size + SIGNATURE_SIZE;
if (!state->buffer) {
state->buffer = mallocz(data_size);
state->buffer_size = data_size;
} else if (state->buffer_size < data_size) {
state->buffer = reallocz(state->buffer, data_size);
state->buffer_size = data_size;
}
memcpy(state->data->stream_buffer + state->data->stream_buffer_pos, data, size);
long int compressed_data_size = LZ4_compress_fast_continue(state->data->stream,
state->data->stream_buffer + state->data->stream_buffer_pos,
state->buffer + SIGNATURE_SIZE, size, max_dst_size, 1);
if (compressed_data_size < 0) {
error("Data compression error: %ld", compressed_data_size);
return 0;
}
state->data->stream_buffer_pos += size;
if (state->data->stream_buffer_pos >= LZ4_STREAM_BUFFER_SIZE - LZ4_MAX_MSG_SIZE)
state->data->stream_buffer_pos = 0;
uint32_t len = ((compressed_data_size & 0x7f) | 0x80 | (((compressed_data_size & (0x7f << 7)) << 1) | 0x8000)) << 8;
*(uint32_t *)state->buffer = len | SIGNATURE;
*out = state->buffer;
debug(D_STREAM, "%s: Compressed data header: %ld", STREAM_COMPRESSION_MSG, compressed_data_size);
return compressed_data_size + SIGNATURE_SIZE;
}
/*
* Create and initialize compressor state
* Return the pointer to compressor_state structure created
*/
struct compressor_state *create_compressor()
{
struct compressor_state *state = callocz(1, sizeof(struct compressor_state));
state->reset = lz4_compressor_reset;
state->compress = lz4_compressor_compress;
state->destroy = lz4_compressor_destroy;
state->data = callocz(1, sizeof(struct compressor_data));
state->data->stream = LZ4_createStream();
state->data->stream_buffer = callocz(1, LZ4_DECODER_RING_BUFFER_SIZE(LZ4_MAX_MSG_SIZE));
state->buffer_size = LZ4_STREAM_BUFFER_SIZE;
state->reset(state);
debug(D_STREAM, "%s: Initialize streaming compression!", STREAM_COMPRESSION_MSG);
return state;
}
/*
* LZ4 streaming API decompressor specific data
*/
struct decompressor_data {
LZ4_streamDecode_t *stream;
char *stream_buffer;
size_t stream_buffer_size;
size_t stream_buffer_pos;
};
/*
* Reset decompressor state for a new stream
*/
static void lz4_decompressor_reset(struct decompressor_state *state)
{
if (state->data) {
if (state->data->stream)
LZ4_setStreamDecode(state->data->stream, NULL, 0);
state->data->stream_buffer_pos = 0;
state->buffer_len = 0;
state->out_buffer_len = 0;
}
}
/*
* Destroy decompressor state and all related data
*/
static void lz4_decompressor_destroy(struct decompressor_state **state)
{
if (state && *state) {
struct decompressor_state *s = *state;
if (s->data) {
debug(D_STREAM, "%s: Destroying decompressor.", STREAM_COMPRESSION_MSG);
if (s->data->stream)
LZ4_freeStreamDecode(s->data->stream);
freez(s->data->stream_buffer);
freez(s->data);
}
freez(s->buffer);
freez(s);
*state = NULL;
}
}
static size_t decode_compress_header(const char *data, size_t data_size)
{
if (!data || !data_size)
return 0;
if (data_size < SIGNATURE_SIZE)
return 0;
uint32_t sign = *(uint32_t *)data;
if ((sign & SIGNATURE_MASK) != SIGNATURE)
return 0;
size_t length = ((sign >> 8) & 0x7f) | ((sign >> 9) & (0x7f << 7));
return length;
}
/*
* Check input data for the compression header
* Return the size of compressed data or 0 for uncompressed data
*/
size_t is_compressed_data(const char *data, size_t data_size)
{
return decode_compress_header(data, data_size);
}
/*
* Start the collection of compressed data in an internal buffer
* Return the size of compressed data or 0 for uncompressed data
*/
static size_t lz4_decompressor_start(struct decompressor_state *state, const char *header, size_t header_size)
{
size_t length = decode_compress_header(header, header_size);
if (!length)
return 0;
if (!state->buffer) {
state->buffer = mallocz(length);
state->buffer_size = length;
} else if (state->buffer_size < length) {
state->buffer = reallocz(state->buffer, length);
state->buffer_size = length;
}
state->buffer_len = length;
state->buffer_pos = 0;
state->out_buffer_pos = 0;
state->out_buffer_len = 0;
return length;
}
/*
* Add a chunk of compressed data to the internal buffer
* Return the current size of compressed data or 0 for error
*/
static size_t lz4_decompressor_put(struct decompressor_state *state, const char *data, size_t size)
{
if (!state || !size || !data)
return 0;
if (!state->buffer)
fatal("STREAM: No decompressor buffer allocated");
if (state->buffer_pos + size > state->buffer_len) {
error("STREAM: Decompressor buffer overflow %lu + %lu > %lu",
state->buffer_pos, size, state->buffer_len
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