1 /*------------------------------------------------------------------------- 2 * 3 * compress_io.h 4 * Interface to compress_io.c routines 5 * 6 * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group 7 * Portions Copyright (c) 1994, Regents of the University of California 8 * 9 * IDENTIFICATION 10 * src/bin/pg_dump/compress_io.h 11 * 12 *------------------------------------------------------------------------- 13 */ 14 15 #ifndef __COMPRESS_IO__ 16 #define __COMPRESS_IO__ 17 18 #include "pg_backup_archiver.h" 19 20 /* Initial buffer sizes used in zlib compression. */ 21 #define ZLIB_OUT_SIZE 4096 22 #define ZLIB_IN_SIZE 4096 23 24 typedef enum 25 { 26 COMPR_ALG_NONE, 27 COMPR_ALG_LIBZ 28 } CompressionAlgorithm; 29 30 /* Prototype for callback function to WriteDataToArchive() */ 31 typedef void (*WriteFunc) (ArchiveHandle *AH, const char *buf, size_t len); 32 33 /* 34 * Prototype for callback function to ReadDataFromArchive() 35 * 36 * ReadDataFromArchive will call the read function repeatedly, until it 37 * returns 0 to signal EOF. ReadDataFromArchive passes a buffer to read the 38 * data into in *buf, of length *buflen. If that's not big enough for the 39 * callback function, it can free() it and malloc() a new one, returning the 40 * new buffer and its size in *buf and *buflen. 41 * 42 * Returns the number of bytes read into *buf, or 0 on EOF. 43 */ 44 typedef size_t (*ReadFunc) (ArchiveHandle *AH, char **buf, size_t *buflen); 45 46 /* struct definition appears in compress_io.c */ 47 typedef struct CompressorState CompressorState; 48 49 extern CompressorState *AllocateCompressor(int compression, WriteFunc writeF); 50 extern void ReadDataFromArchive(ArchiveHandle *AH, int compression, 51 ReadFunc readF); 52 extern void WriteDataToArchive(ArchiveHandle *AH, CompressorState *cs, 53 const void *data, size_t dLen); 54 extern void EndCompressor(ArchiveHandle *AH, CompressorState *cs); 55 56 57 typedef struct cfp cfp; 58 59 extern cfp *cfopen(const char *path, const char *mode, int compression); 60 extern cfp *cfopen_read(const char *path, const char *mode); 61 extern cfp *cfopen_write(const char *path, const char *mode, int compression); 62 extern int cfread(void *ptr, int size, cfp *fp); 63 extern int cfwrite(const void *ptr, int size, cfp *fp); 64 extern int cfgetc(cfp *fp); 65 extern char *cfgets(cfp *fp, char *buf, int len); 66 extern int cfclose(cfp *fp); 67 extern int cfeof(cfp *fp); 68 extern const char *get_cfp_error(cfp *fp); 69 70 #endif 71