mirror of
https://github.com/SerenityOS/serenity
synced 2024-09-06 17:06:31 +00:00
83 lines
2.2 KiB
C++
83 lines
2.2 KiB
C++
#define _FILE_OFFSET_BITS 64
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#include "FileBackedDiskDevice.h"
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#include <cstring>
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#include <sys/stat.h>
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//#define FBBD_DEBUG
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#define IGNORE_FILE_LENGTH // Useful for e.g /dev/hda2
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RetainPtr<FileBackedDiskDevice> FileBackedDiskDevice::create(String&& image_path, unsigned block_size)
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{
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return adopt(*new FileBackedDiskDevice(move(image_path), block_size));
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}
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FileBackedDiskDevice::FileBackedDiskDevice(String&& image_path, unsigned block_size)
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: m_image_path(move(image_path))
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, m_block_size(block_size)
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{
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struct stat st;
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int result = stat(m_image_path.characters(), &st);
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ASSERT(result != -1);
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m_file_length = st.st_size;
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m_file = fopen(m_image_path.characters(), "r+");
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}
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FileBackedDiskDevice::~FileBackedDiskDevice()
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{
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}
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unsigned FileBackedDiskDevice::block_size() const
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{
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return m_block_size;
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}
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bool FileBackedDiskDevice::read_block(unsigned index, byte* out) const
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{
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DiskOffset offset = index * m_block_size;
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return read_internal(offset, block_size(), out);
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}
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bool FileBackedDiskDevice::write_block(unsigned index, const byte* data)
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{
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DiskOffset offset = index * m_block_size;
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return write_internal(offset, block_size(), data);
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}
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bool FileBackedDiskDevice::read_internal(DiskOffset offset, unsigned length, byte* out) const
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{
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#ifndef IGNORE_FILE_LENGTH
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if (offset + length >= m_file_length)
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return false;
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#endif
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#ifdef FBBD_DEBUG
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printf("[FileBackedDiskDevice] Read device @ offset %llx, length %u\n", offset, length);
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#endif
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fseeko(m_file, offset, SEEK_SET);
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unsigned nread = fread(out, sizeof(byte), length, m_file);
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ASSERT(nread == length);
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return true;
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}
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bool FileBackedDiskDevice::write_internal(DiskOffset offset, unsigned length, const byte* data)
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{
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#ifndef IGNORE_FILE_LENGTH
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if (offset + length >= m_file_length)
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return false;
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#endif
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#ifdef FBBD_DEBUG
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printf("[FileBackedDiskDevice] Write device @ offset %llx, length %u\n", offset, length);
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#endif
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fseeko(m_file, offset, SEEK_SET);
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// size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream);
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unsigned nwritten = fwrite(data, sizeof(byte), length, m_file);
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ASSERT(nwritten == length);
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return true;
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}
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const char* FileBackedDiskDevice::class_name() const
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{
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return "FileBackedDiskDevice";
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}
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