godot/core/io/file_access_compressed.cpp
Rémi Verschelde a7f49ac9a1 Update copyright statements to 2020
Happy new year to the wonderful Godot community!

We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.

Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
2020-01-01 11:16:22 +01:00

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/*************************************************************************/
/* file_access_compressed.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 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/print_string.h"
void FileAccessCompressed::configure(const String &p_magic, Compression::Mode p_mode, int 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();
read_total = f->get_32();
int bc = (read_total / block_size) + 1;
int acc_ofs = f->get_position() + bc * 4;
int max_bs = 0;
for (int 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 = NULL;
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) {
memdelete(f);
f = NULL;
return ERR_FILE_UNRECOGNIZED;
}
open_after_magic(f);
}
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
int bc = (write_max / block_size) + 1;
for (int i = 0; i < bc; i++) {
f->store_32(0); //compressed sizes, will update later
}
Vector<int> block_sizes;
for (int i = 0; i < bc; i++) {
int 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 (int 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 = NULL;
}
bool FileAccessCompressed::is_open() const {
return f != NULL;
}
void FileAccessCompressed::seek(size_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;
int 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);
}
}
size_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;
}
}
size_t FileAccessCompressed::get_len() 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;
}
int FileAccessCompressed::get_buffer(uint8_t *p_dst, int p_length) 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;
}
for (int 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 read 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 read 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() :
cmode(Compression::MODE_ZSTD),
writing(false),
write_ptr(0),
write_buffer_size(0),
write_max(0),
block_size(0),
read_eof(false),
at_end(false),
read_ptr(NULL),
read_block(0),
read_block_count(0),
read_block_size(0),
read_pos(0),
read_total(0),
magic("GCMP"),
f(NULL) {
}
FileAccessCompressed::~FileAccessCompressed() {
if (f)
close();
}