dec/streams.h

   1 /* Copyright 2013 Google Inc. All Rights Reserved.
   2
   3    Distributed under MIT license.
   4    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
   5 */
   6
   7 /* Functions for streaming input and output. */
   8
   9 #ifndef BROTLI_DEC_STREAMS_H_
  10 #define BROTLI_DEC_STREAMS_H_
  11
  12 #include <stdio.h>
  13 #include "./port.h"
  14 #include "./types.h"
  15
  16 #if defined(__cplusplus) || defined(c_plusplus)
  17 extern "C" {
  18 #endif
  19
  20 /* Function pointer type used to read len bytes into buf. Returns the */
  21 /* number of bytes read or -1 on error. */
  22 typedef int (*BrotliInputFunction)(void* data, uint8_t* buf, size_t len);
  23
  24 /* Input callback function with associated data. */
  25 typedef struct {
  26   BrotliInputFunction cb_;
  27   void* data_;
  28 } BrotliInput;
  29
  30 /* Reads len bytes into buf, using the in callback. */
  31 static BROTLI_INLINE int BrotliRead(BrotliInput in, uint8_t* buf, size_t len) {
  32   return in.cb_(in.data_, buf, len);
  33 }
  34
  35 /* Function pointer type used to write len bytes into buf. Returns the */
  36 /* number of bytes written or -1 on error. */
  37 typedef int (*BrotliOutputFunction)(void* data, const uint8_t* buf, size_t len);
  38
  39 /* Output callback function with associated data. */
  40 typedef struct {
  41   BrotliOutputFunction cb_;
  42   void* data_;
  43 } BrotliOutput;
  44
  45 /* Writes len bytes into buf, using the out callback. */
  46 static BROTLI_INLINE int BrotliWrite(BrotliOutput out,
  47                                      const uint8_t* buf, size_t len) {
  48   return out.cb_(out.data_, buf, len);
  49 }
  50
  51 /* Memory region with position. */
  52 typedef struct {
  53   const uint8_t* buffer;
  54   size_t length;
  55   size_t pos;
  56 } BrotliMemInput;
  57
  58 /* Input callback where *data is a BrotliMemInput struct. */
  59 int BrotliMemInputFunction(void* data, uint8_t* buf, size_t count);
  60
  61 /* Returns an input callback that wraps the given memory region. */
  62 BrotliInput BrotliInitMemInput(const uint8_t* buffer, size_t length,
  63                                BrotliMemInput* mem_input);
  64
  65 /* Output buffer with position. */
  66 typedef struct {
  67   uint8_t* buffer;
  68   size_t length;
  69   size_t pos;
  70 } BrotliMemOutput;
  71
  72 /* Output callback where *data is a BrotliMemOutput struct. */
  73 int BrotliMemOutputFunction(void* data, const uint8_t* buf, size_t count);
  74
  75 /* Returns an output callback that wraps the given memory region. */
  76 BrotliOutput BrotliInitMemOutput(uint8_t* buffer, size_t length,
  77                                  BrotliMemOutput* mem_output);
  78
  79 /* Input callback that reads from a file. */
  80 int BrotliFileInputFunction(void* data, uint8_t* buf, size_t count);
  81 BrotliInput BrotliFileInput(FILE* f);
  82
  83 /* Output callback that writes to a file. */
  84 int BrotliFileOutputFunction(void* data, const uint8_t* buf, size_t count);
  85 BrotliOutput BrotliFileOutput(FILE* f);
  86
  87 /* Output callback that does nothing, always consumes the whole input. */
  88 int BrotliNullOutputFunction(void* data, const uint8_t* buf, size_t count);
  89 BrotliOutput BrotliNullOutput(void);
  90
  91 #if defined(__cplusplus) || defined(c_plusplus)
  92 }    /* extern "C" */
  93 #endif
  94
  95 #endif  /* BROTLI_DEC_STREAMS_H_ */