/*------------------------------------------------------------------------- * * compress_io.h * Interface to compress_io.c routines * * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION * src/bin/pg_dump/compress_io.h * *------------------------------------------------------------------------- */ #ifndef __COMPRESS_IO__ #define __COMPRESS_IO__ #include "postgres_fe.h" #include "pg_backup_archiver.h" /* Initial buffer sizes used in zlib compression. */ #define ZLIB_OUT_SIZE 4096 #define ZLIB_IN_SIZE 4096 typedef enum { COMPR_ALG_NONE, COMPR_ALG_LIBZ } CompressionAlgorithm; /* Prototype for callback function to WriteDataToArchive() */ typedef size_t (*WriteFunc)(ArchiveHandle *AH, const char *buf, size_t len); /* * Prototype for callback function to ReadDataFromArchive() * * ReadDataFromArchive will call the read function repeatedly, until it * returns 0 to signal EOF. ReadDataFromArchive passes a buffer to read the * data into in *buf, of length *buflen. If that's not big enough for the * callback function, it can free() it and malloc() a new one, returning the * new buffer and its size in *buf and *buflen. * * Returns the number of bytes read into *buf, or 0 on EOF. */ typedef size_t (*ReadFunc)(ArchiveHandle *AH, char **buf, size_t *buflen); /* struct definition appears in compress_io.c */ typedef struct CompressorState CompressorState; extern CompressorState *AllocateCompressor(int compression, WriteFunc writeF); extern void ReadDataFromArchive(ArchiveHandle *AH, int compression, ReadFunc readF); extern size_t WriteDataToArchive(ArchiveHandle *AH, CompressorState *cs, const void *data, size_t dLen); extern void EndCompressor(ArchiveHandle *AH, CompressorState *cs); #endif