brotli/dec/streams.h

// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Functions for streaming input and output.

#ifndef BROTLI_DEC_STREAMS_H_
#define BROTLI_DEC_STREAMS_H_

#include <stdio.h>
#include "./types.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

// Function pointer type used to read len bytes into buf. Returns the
// number of bytes read or -1 on error.
typedef int (*BrotliInputFunction)(void* data, uint8_t* buf, size_t len);

// Input callback function with associated data.
typedef struct {
  BrotliInputFunction cb_;
  void* data_;
} BrotliInput;

// Reads len bytes into buf, using the in callback.
static BROTLI_INLINE int BrotliRead(BrotliInput in, uint8_t* buf, size_t len) {
  return in.cb_(in.data_, buf, len);
}

// Function pointer type used to write len bytes into buf. Returns the
// number of bytes written or -1 on error.
typedef int (*BrotliOutputFunction)(void* data, const uint8_t* buf, size_t len);

// Output callback function with associated data.
typedef struct {
  BrotliOutputFunction cb_;
  void* data_;
} BrotliOutput;

// Writes len bytes into buf, using the out callback.
static BROTLI_INLINE int BrotliWrite(BrotliOutput out,
                                     const uint8_t* buf, size_t len) {
  return out.cb_(out.data_, buf, len);
}

// Memory region with position.
typedef struct {
  const uint8_t* buffer;
  size_t length;
  size_t pos;
} BrotliMemInput;

// Input callback where *data is a BrotliMemInput struct.
int BrotliMemInputFunction(void* data, uint8_t* buf, size_t count);

// Returns an input callback that wraps the given memory region.
BrotliInput BrotliInitMemInput(const uint8_t* buffer, size_t length,
                               BrotliMemInput* mem_input);

// Output buffer with position.
typedef struct {
  uint8_t* buffer;
  size_t length;
  size_t pos;
} BrotliMemOutput;

// Output callback where *data is a BrotliMemOutput struct.
int BrotliMemOutputFunction(void* data, const uint8_t* buf, size_t count);

// Returns an output callback that wraps the given memory region.
BrotliOutput BrotliInitMemOutput(uint8_t* buffer, size_t length,
                                 BrotliMemOutput* mem_output);

// Input callback that reads from standard input.
int BrotliStdinInputFunction(void* data, uint8_t* buf, size_t count);
BrotliInput BrotliStdinInput();

// Output callback that writes to standard output.
int BrotliStdoutOutputFunction(void* data, const uint8_t* buf, size_t count);
BrotliOutput BrotliStdoutOutput();

// Output callback that writes to a file.
int BrotliFileOutputFunction(void* data, const uint8_t* buf, size_t count);
BrotliOutput BrotliFileOutput(FILE* f);

#if defined(__cplusplus) || defined(c_plusplus)
}    // extern "C"
#endif

#endif  // BROTLI_DEC_STREAMS_H_