godot/core/io/file_access_compressed.cpp
2021-05-25 11:54:28 +01:00

381 lines
11 KiB
C++

/*************************************************************************/
/* file_access_compressed.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "file_access_compressed.h"
#include "core/string/print_string.h"
void FileAccessCompressed::configure(const String &p_magic, Compression::Mode p_mode, uint32_t p_block_size) {
magic = p_magic.ascii().get_data();
if (magic.length() > 4) {
magic = magic.substr(0, 4);
} else {
while (magic.length() < 4) {
magic += " ";
}
}
cmode = p_mode;
block_size = p_block_size;
}
#define WRITE_FIT(m_bytes) \
{ \
if (write_pos + (m_bytes) > write_max) { \
write_max = write_pos + (m_bytes); \
} \
if (write_max > write_buffer_size) { \
write_buffer_size = next_power_of_2(write_max); \
buffer.resize(write_buffer_size); \
write_ptr = buffer.ptrw(); \
} \
}
Error FileAccessCompressed::open_after_magic(FileAccess *p_base) {
f = p_base;
cmode = (Compression::Mode)f->get_32();
block_size = f->get_32();
if (block_size == 0) {
f = nullptr; // Let the caller to handle the FileAccess object if failed to open as compressed file.
ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, "Can't open compressed file '" + p_base->get_path() + "' with block size 0, it is corrupted.");
}
read_total = f->get_32();
uint32_t bc = (read_total / block_size) + 1;
uint64_t acc_ofs = f->get_position() + bc * 4;
uint32_t max_bs = 0;
for (uint32_t i = 0; i < bc; i++) {
ReadBlock rb;
rb.offset = acc_ofs;
rb.csize = f->get_32();
acc_ofs += rb.csize;
max_bs = MAX(max_bs, rb.csize);
read_blocks.push_back(rb);
}
comp_buffer.resize(max_bs);
buffer.resize(block_size);
read_ptr = buffer.ptrw();
f->get_buffer(comp_buffer.ptrw(), read_blocks[0].csize);
at_end = false;
read_eof = false;
read_block_count = bc;
read_block_size = read_blocks.size() == 1 ? read_total : block_size;
Compression::decompress(buffer.ptrw(), read_block_size, comp_buffer.ptr(), read_blocks[0].csize, cmode);
read_block = 0;
read_pos = 0;
return OK;
}
Error FileAccessCompressed::_open(const String &p_path, int p_mode_flags) {
ERR_FAIL_COND_V(p_mode_flags == READ_WRITE, ERR_UNAVAILABLE);
if (f) {
close();
}
Error err;
f = FileAccess::open(p_path, p_mode_flags, &err);
if (err != OK) {
//not openable
f = nullptr;
return err;
}
if (p_mode_flags & WRITE) {
buffer.clear();
writing = true;
write_pos = 0;
write_buffer_size = 256;
buffer.resize(256);
write_max = 0;
write_ptr = buffer.ptrw();
//don't store anything else unless it's done saving!
} else {
char rmagic[5];
f->get_buffer((uint8_t *)rmagic, 4);
rmagic[4] = 0;
if (magic != rmagic || open_after_magic(f) != OK) {
memdelete(f);
f = nullptr;
return ERR_FILE_UNRECOGNIZED;
}
}
return OK;
}
void FileAccessCompressed::close() {
if (!f) {
return;
}
if (writing) {
//save block table and all compressed blocks
CharString mgc = magic.utf8();
f->store_buffer((const uint8_t *)mgc.get_data(), mgc.length()); //write header 4
f->store_32(cmode); //write compression mode 4
f->store_32(block_size); //write block size 4
f->store_32(write_max); //max amount of data written 4
uint32_t bc = (write_max / block_size) + 1;
for (uint32_t i = 0; i < bc; i++) {
f->store_32(0); //compressed sizes, will update later
}
Vector<int> block_sizes;
for (uint32_t i = 0; i < bc; i++) {
uint32_t bl = i == (bc - 1) ? write_max % block_size : block_size;
uint8_t *bp = &write_ptr[i * block_size];
Vector<uint8_t> cblock;
cblock.resize(Compression::get_max_compressed_buffer_size(bl, cmode));
int s = Compression::compress(cblock.ptrw(), bp, bl, cmode);
f->store_buffer(cblock.ptr(), s);
block_sizes.push_back(s);
}
f->seek(16); //ok write block sizes
for (uint32_t i = 0; i < bc; i++) {
f->store_32(block_sizes[i]);
}
f->seek_end();
f->store_buffer((const uint8_t *)mgc.get_data(), mgc.length()); //magic at the end too
buffer.clear();
} else {
comp_buffer.clear();
buffer.clear();
read_blocks.clear();
}
memdelete(f);
f = nullptr;
}
bool FileAccessCompressed::is_open() const {
return f != nullptr;
}
void FileAccessCompressed::seek(uint64_t p_position) {
ERR_FAIL_COND_MSG(!f, "File must be opened before use.");
if (writing) {
ERR_FAIL_COND(p_position > write_max);
write_pos = p_position;
} else {
ERR_FAIL_COND(p_position > read_total);
if (p_position == read_total) {
at_end = true;
} else {
at_end = false;
read_eof = false;
uint32_t block_idx = p_position / block_size;
if (block_idx != read_block) {
read_block = block_idx;
f->seek(read_blocks[read_block].offset);
f->get_buffer(comp_buffer.ptrw(), read_blocks[read_block].csize);
Compression::decompress(buffer.ptrw(), read_blocks.size() == 1 ? read_total : block_size, comp_buffer.ptr(), read_blocks[read_block].csize, cmode);
read_block_size = read_block == read_block_count - 1 ? read_total % block_size : block_size;
}
read_pos = p_position % block_size;
}
}
}
void FileAccessCompressed::seek_end(int64_t p_position) {
ERR_FAIL_COND_MSG(!f, "File must be opened before use.");
if (writing) {
seek(write_max + p_position);
} else {
seek(read_total + p_position);
}
}
uint64_t FileAccessCompressed::get_position() const {
ERR_FAIL_COND_V_MSG(!f, 0, "File must be opened before use.");
if (writing) {
return write_pos;
} else {
return read_block * block_size + read_pos;
}
}
uint64_t FileAccessCompressed::get_length() const {
ERR_FAIL_COND_V_MSG(!f, 0, "File must be opened before use.");
if (writing) {
return write_max;
} else {
return read_total;
}
}
bool FileAccessCompressed::eof_reached() const {
ERR_FAIL_COND_V_MSG(!f, false, "File must be opened before use.");
if (writing) {
return false;
} else {
return read_eof;
}
}
uint8_t FileAccessCompressed::get_8() const {
ERR_FAIL_COND_V_MSG(!f, 0, "File must be opened before use.");
ERR_FAIL_COND_V_MSG(writing, 0, "File has not been opened in read mode.");
if (at_end) {
read_eof = true;
return 0;
}
uint8_t ret = read_ptr[read_pos];
read_pos++;
if (read_pos >= read_block_size) {
read_block++;
if (read_block < read_block_count) {
//read another block of compressed data
f->get_buffer(comp_buffer.ptrw(), read_blocks[read_block].csize);
Compression::decompress(buffer.ptrw(), read_blocks.size() == 1 ? read_total : block_size, comp_buffer.ptr(), read_blocks[read_block].csize, cmode);
read_block_size = read_block == read_block_count - 1 ? read_total % block_size : block_size;
read_pos = 0;
} else {
read_block--;
at_end = true;
}
}
return ret;
}
uint64_t FileAccessCompressed::get_buffer(uint8_t *p_dst, uint64_t p_length) const {
ERR_FAIL_COND_V(!p_dst && p_length > 0, -1);
ERR_FAIL_COND_V_MSG(!f, -1, "File must be opened before use.");
ERR_FAIL_COND_V_MSG(writing, -1, "File has not been opened in read mode.");
if (at_end) {
read_eof = true;
return 0;
}
for (uint64_t i = 0; i < p_length; i++) {
p_dst[i] = read_ptr[read_pos];
read_pos++;
if (read_pos >= read_block_size) {
read_block++;
if (read_block < read_block_count) {
//read another block of compressed data
f->get_buffer(comp_buffer.ptrw(), read_blocks[read_block].csize);
Compression::decompress(buffer.ptrw(), read_blocks.size() == 1 ? read_total : block_size, comp_buffer.ptr(), read_blocks[read_block].csize, cmode);
read_block_size = read_block == read_block_count - 1 ? read_total % block_size : block_size;
read_pos = 0;
} else {
read_block--;
at_end = true;
if (i < p_length - 1) {
read_eof = true;
}
return i;
}
}
}
return p_length;
}
Error FileAccessCompressed::get_error() const {
return read_eof ? ERR_FILE_EOF : OK;
}
void FileAccessCompressed::flush() {
ERR_FAIL_COND_MSG(!f, "File must be opened before use.");
ERR_FAIL_COND_MSG(!writing, "File has not been opened in write mode.");
// compressed files keep data in memory till close()
}
void FileAccessCompressed::store_8(uint8_t p_dest) {
ERR_FAIL_COND_MSG(!f, "File must be opened before use.");
ERR_FAIL_COND_MSG(!writing, "File has not been opened in write mode.");
WRITE_FIT(1);
write_ptr[write_pos++] = p_dest;
}
bool FileAccessCompressed::file_exists(const String &p_name) {
FileAccess *fa = FileAccess::open(p_name, FileAccess::READ);
if (!fa) {
return false;
}
memdelete(fa);
return true;
}
uint64_t FileAccessCompressed::_get_modified_time(const String &p_file) {
if (f) {
return f->get_modified_time(p_file);
} else {
return 0;
}
}
uint32_t FileAccessCompressed::_get_unix_permissions(const String &p_file) {
if (f) {
return f->_get_unix_permissions(p_file);
}
return 0;
}
Error FileAccessCompressed::_set_unix_permissions(const String &p_file, uint32_t p_permissions) {
if (f) {
return f->_set_unix_permissions(p_file, p_permissions);
}
return FAILED;
}
FileAccessCompressed::~FileAccessCompressed() {
if (f) {
close();
}
}