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CLK/Storage/FileHolder.cpp
2016-12-30 19:59:01 -05:00

101 lines
2.1 KiB
C++

//
// FileHolder.cpp
// Clock Signal
//
// Created by Thomas Harte on 21/11/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#include "FileHolder.hpp"
#include <cstring>
using namespace Storage;
FileHolder::~FileHolder()
{
if(file_) fclose(file_);
}
FileHolder::FileHolder(const char *file_name) : file_(nullptr)
{
stat(file_name, &file_stats_);
is_read_only_ = false;
file_ = fopen(file_name, "rb+");
if(!file_)
{
is_read_only_ = true;
file_ = fopen(file_name, "rb");
}
if(!file_) throw ErrorCantOpen;
}
bool FileHolder::check_signature(const char *signature, size_t length)
{
if(!length) length = strlen(signature)+1;
// read and check the file signature
char stored_signature[12];
if(fread(stored_signature, 1, length, file_) != length) return false;
if(memcmp(stored_signature, signature, length)) return false;
return true;
}
uint32_t FileHolder::fgetc32le()
{
uint32_t result = (uint32_t)fgetc(file_);
result |= (uint32_t)(fgetc(file_) << 8);
result |= (uint32_t)(fgetc(file_) << 16);
result |= (uint32_t)(fgetc(file_) << 24);
return result;
}
uint32_t FileHolder::fgetc24le()
{
uint32_t result = (uint32_t)fgetc(file_);
result |= (uint32_t)(fgetc(file_) << 8);
result |= (uint32_t)(fgetc(file_) << 16);
return result;
}
uint16_t FileHolder::fgetc16le()
{
uint16_t result = (uint16_t)fgetc(file_);
result |= (uint16_t)(fgetc(file_) << 8);
return result;
}
uint32_t FileHolder::fgetc32be()
{
uint32_t result = (uint32_t)(fgetc(file_) << 24);
result |= (uint32_t)(fgetc(file_) << 16);
result |= (uint32_t)(fgetc(file_) << 8);
result |= (uint32_t)fgetc(file_);
return result;
}
uint16_t FileHolder::fgetc16be()
{
uint16_t result = (uint16_t)(fgetc(file_) << 8);
result |= (uint16_t)fgetc(file_);
return result;
}
void FileHolder::ensure_file_is_at_least_length(long length)
{
fseek(file_, 0, SEEK_END);
long bytes_to_write = length - ftell(file_);
if(bytes_to_write > 0)
{
uint8_t *empty = new uint8_t[bytes_to_write];
memset(empty, 0, (size_t)bytes_to_write);
fwrite(empty, sizeof(uint8_t), (size_t)bytes_to_write, file_);
delete[] empty;
}
}