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@justinmeiners
Last active October 25, 2022 20:43
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Read an entire file into a buffer (without race conditions or seeking).
void* fread_all(FILE* file, size_t* out_size) {
const size_t BLOCK_SIZE = 32 * 1024;
const size_t MEDIUM_SIZE = 10 * 1024 * 1024;
*out_size = 0;
size_t cap = 0;
char* data = NULL;
while (1) {
if (*out_size + BLOCK_SIZE > cap) {
if (cap > MEDIUM_SIZE) {
cap = (cap * 3) / 2;
} else if (cap < BLOCK_SIZE) {
cap = BLOCK_SIZE;
} else {
cap *= 2;
}
void* new_data = realloc(data, cap);
if (!new_data) {
*out_size = 0;
free(data);
return NULL;
}
data = new_data;
}
size_t read = fread(data + *out_size, 1, BLOCK_SIZE, file);
*out_size += read;
if (read < BLOCK_SIZE) {
if (ferror(file)) {
*out_size = 0;
free(data);
return NULL;
} else {
return data;
}
}
}
}
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