imageio_util.c
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// Copyright 2016 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Utility functions used by the image decoders.
//
#include "./imageio_util.h"
#if defined(_WIN32)
#include <fcntl.h> // for _O_BINARY
#include <io.h> // for _setmode()
#endif
#include <stdlib.h>
#include <string.h>
// -----------------------------------------------------------------------------
// File I/O
FILE* ImgIoUtilSetBinaryMode(FILE* file) {
#if defined(_WIN32)
if (_setmode(_fileno(file), _O_BINARY) == -1) {
fprintf(stderr, "Failed to reopen file in O_BINARY mode.\n");
return NULL;
}
#endif
return file;
}
int ImgIoUtilReadFromStdin(const uint8_t** data, size_t* data_size) {
static const size_t kBlockSize = 16384; // default initial size
size_t max_size = 0;
size_t size = 0;
uint8_t* input = NULL;
if (data == NULL || data_size == NULL) return 0;
*data = NULL;
*data_size = 0;
if (!ImgIoUtilSetBinaryMode(stdin)) return 0;
while (!feof(stdin)) {
// We double the buffer size each time and read as much as possible.
const size_t extra_size = (max_size == 0) ? kBlockSize : max_size;
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// we allocate one extra byte for the \0 terminator
void* const new_data = realloc(input, max_size + extra_size + 1);
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if (new_data == NULL) goto Error;
input = (uint8_t*)new_data;
max_size += extra_size;
size += fread(input + size, 1, extra_size, stdin);
if (size < max_size) break;
}
if (ferror(stdin)) goto Error;
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if (input != NULL) input[size] = '\0'; // convenient 0-terminator
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*data = input;
*data_size = size;
return 1;
Error:
free(input);
fprintf(stderr, "Could not read from stdin\n");
return 0;
}
int ImgIoUtilReadFile(const char* const file_name,
const uint8_t** data, size_t* data_size) {
int ok;
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uint8_t* file_data;
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size_t file_size;
FILE* in;
const int from_stdin = (file_name == NULL) || !strcmp(file_name, "-");
if (from_stdin) return ImgIoUtilReadFromStdin(data, data_size);
if (data == NULL || data_size == NULL) return 0;
*data = NULL;
*data_size = 0;
in = fopen(file_name, "rb");
if (in == NULL) {
fprintf(stderr, "cannot open input file '%s'\n", file_name);
return 0;
}
fseek(in, 0, SEEK_END);
file_size = ftell(in);
fseek(in, 0, SEEK_SET);
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// we allocate one extra byte for the \0 terminator
file_data = (uint8_t*)malloc(file_size + 1);
if (file_data == NULL) {
fclose(in);
fprintf(stderr, "memory allocation failure when reading file %s\n",
file_name);
return 0;
}
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ok = (fread(file_data, file_size, 1, in) == 1);
fclose(in);
if (!ok) {
fprintf(stderr, "Could not read %d bytes of data from file %s\n",
(int)file_size, file_name);
free(file_data);
return 0;
}
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file_data[file_size] = '\0'; // convenient 0-terminator
*data = file_data;
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*data_size = file_size;
return 1;
}
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// -----------------------------------------------------------------------------
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int ImgIoUtilWriteFile(const char* const file_name,
const uint8_t* data, size_t data_size) {
int ok;
FILE* out;
const int to_stdout = (file_name == NULL) || !strcmp(file_name, "-");
if (data == NULL) {
return 0;
}
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out = to_stdout ? ImgIoUtilSetBinaryMode(stdout) : fopen(file_name, "wb");
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if (out == NULL) {
fprintf(stderr, "Error! Cannot open output file '%s'\n", file_name);
return 0;
}
ok = (fwrite(data, data_size, 1, out) == 1);
if (out != stdout) fclose(out);
return ok;
}
// -----------------------------------------------------------------------------
void ImgIoUtilCopyPlane(const uint8_t* src, int src_stride,
uint8_t* dst, int dst_stride, int width, int height) {
while (height-- > 0) {
memcpy(dst, src, width * sizeof(*dst));
src += src_stride;
dst += dst_stride;
}
}
// -----------------------------------------------------------------------------
int ImgIoUtilCheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
const uint64_t total_size = nmemb * size;
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int ok = (total_size == (size_t)total_size);
#if defined(WEBP_MAX_IMAGE_SIZE)
ok = ok && (total_size <= (uint64_t)WEBP_MAX_IMAGE_SIZE);
#endif
return ok;
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}
// -----------------------------------------------------------------------------