#ifndef IOSTREAM_LZ4_H
#define IOSTREAM_LZ4_H
/*
Dovecot's LZ4 compressed files contain:
IOSTREAM_LZ4_HEADER
n x (4 byte big-endian: compressed chunk length, compressed chunk)
*/
#define IOSTREAM_LZ4_MAGIC "Dovecot-LZ4\x0d\x2a\x9b\xc5"
#define IOSTREAM_LZ4_MAGIC_LEN (sizeof(IOSTREAM_LZ4_MAGIC)-1)
struct iostream_lz4_header {
unsigned char magic[IOSTREAM_LZ4_MAGIC_LEN];
/* OSTREAM_LZ4_CHUNK_SIZE in big-endian */
unsigned char max_uncompressed_chunk_size[4];
};
/* How large chunks we're buffering into memory before compressing them */
#define OSTREAM_LZ4_CHUNK_SIZE (1024*64)
/* How large chunks we allow in input data before returning a failure.
This must be at least OSTREAM_LZ4_CHUNK_SIZE, but for future compatibility
should be somewhat higher (but not too high to avoid wasting memory for
corrupted files). */
#define ISTREAM_LZ4_CHUNK_SIZE (1024*1024)
#define IOSTREAM_LZ4_CHUNK_PREFIX_LEN 4 /* big-endian size of chunk */
#endif