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open_toontown_panda3d/panda/src/express/patchfile.cxx

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/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file patchfile.cxx
* @author darren, mike
* @date 1997-01-09
*/
#include "pandabase.h"
#ifdef HAVE_OPENSSL
#include "config_express.h"
#include "error_utils.h"
#include "patchfile.h"
#include "streamReader.h"
#include "streamWriter.h"
#include "multifile.h"
#include "hashVal.h"
#include "virtualFileSystem.h"
#include <string.h> // for strstr
#ifdef HAVE_TAR
#include <libtar.h>
#include <fcntl.h> // for O_RDONLY
#endif // HAVE_TAR
#ifdef HAVE_TAR
std::istream *Patchfile::_tar_istream = nullptr;
#endif // HAVE_TAR
using std::endl;
using std::ios;
using std::istream;
using std::min;
using std::ostream;
using std::streampos;
using std::string;
// this actually slows things down... #define
// USE_MD5_FOR_HASHTABLE_INDEX_VALUES
/*
* Patch File Format IF THIS CHANGES, UPDATE installerApplyPatch.cxx IN THE
* INSTALLER [ HEADER ] 4 bytes 0xfeebfaac ("magic number") (older patch
* files have a magic number 0xfeebfaab, indicating they are version number
* 0.) 2 bytes version number (if magic number == 0xfeebfaac) 4 bytes length
* of starting file (if version >= 1) 16 bytes MD5 of starting file (if
* version >= 1) 4 bytes length of resulting patched file 16 bytes MD5 of
* resultant patched file Note that MD5 hashes are written in the order
* observed by HashVal::read_stream() and HashVal::write_stream(), which is
* not the normal linear order. (Each group of four bytes is reversed.)
*/
const int _v0_header_length = 4 + 4 + 16;
const int _v1_header_length = 4 + 2 + 4 + 16 + 4 + 16;
/*
* [ ADDCOPY pairs; repeated N times ] 2 bytes AL = ADD length AL bytes
* bytes to add 2 bytes CL = COPY length 4 bytes offset of data to copy from
* original file, if CL != 0. If version >= 2, offset is relative to end of
* previous copy block; if version < 2, offset is relative to beginning of
* file. [ TERMINATOR ] 2 bytes zero-length ADD 2 bytes zero-length COPY
*/
// Defines
const uint32_t Patchfile::_v0_magic_number = 0xfeebfaab;
const uint32_t Patchfile::_magic_number = 0xfeebfaac;
// Created version 1 on 11202 to store length and MD5 of original file. To
// version 2 on 11202 to store copy offsets as relative.
const uint16_t Patchfile::_current_version = 2;
const uint32_t Patchfile::_HASH_BITS = 24;
const uint32_t Patchfile::_HASHTABLESIZE = uint32_t(1) << Patchfile::_HASH_BITS;
const uint32_t Patchfile::_DEFAULT_FOOTPRINT_LENGTH = 9; // this produced the smallest patch file for libpanda.dll when tested, 12/20/2000
const uint32_t Patchfile::_NULL_VALUE = uint32_t(0) - 1;
const uint32_t Patchfile::_MAX_RUN_LENGTH = (uint32_t(1) << 16) - 1;
const uint32_t Patchfile::_HASH_MASK = (uint32_t(1) << Patchfile::_HASH_BITS) - 1;
/**
* Create a patch file and initializes internal data
*/
Patchfile::
Patchfile() {
PT(Buffer) buffer = new Buffer(patchfile_buffer_size);
init(buffer);
}
/**
* Create patch file with buffer to patch
*/
Patchfile::
Patchfile(PT(Buffer) buffer) {
init(buffer);
}
/**
*
*/
void Patchfile::
init(PT(Buffer) buffer) {
_rename_output_to_orig = false;
_delete_patchfile = false;
_hash_table = nullptr;
_initiated = false;
nassertv(!buffer.is_null());
_buffer = buffer;
_version_number = 0;
_allow_multifile = true;
_patch_stream = nullptr;
_origfile_stream = nullptr;
reset_footprint_length();
}
/**
*
*/
Patchfile::
~Patchfile() {
if (_hash_table != nullptr) {
PANDA_FREE_ARRAY(_hash_table);
}
if (_initiated) {
cleanup();
}
nassertv(_patch_stream == nullptr);
nassertv(_origfile_stream == nullptr);
}
/**
* Closes and clean up internal data structures
*/
void Patchfile::
cleanup() {
if (!_initiated) {
express_cat.error()
<< "Patchfile::cleanup() - Patching has not been initiated"
<< endl;
return;
}
// close files
VirtualFileSystem *vfs = VirtualFileSystem::get_global_ptr();
if (_origfile_stream != nullptr) {
vfs->close_read_file(_origfile_stream);
_origfile_stream = nullptr;
}
if (_patch_stream != nullptr) {
vfs->close_read_file(_patch_stream);
_patch_stream = nullptr;
}
_write_stream.close();
_initiated = false;
}
// PATCH FILE APPLY MEMBER FUNCTIONS
// NOTE: this patch-application functionality unfortunately has to be
// duplicated in the Installer. It is contained in the file
// installerApplyPatch.cxx PLEASE MAKE SURE THAT THAT FILE GETS UPDATED IF ANY
// OF THIS LOGIC CHANGES! (i.e. if the patch file format changes)
/**
* Set up to apply the patch to the file (original file and patch are
* destroyed in the process).
*/
int Patchfile::
initiate(const Filename &patch_file, const Filename &file) {
int result = initiate(patch_file, file, Filename::temporary("", "patch_"));
_rename_output_to_orig = true;
_delete_patchfile = !keep_temporary_files;
return result;
}
/**
* Set up to apply the patch to the file. In this form, neither the original
* file nor the patch file are destroyed.
*/
int Patchfile::
initiate(const Filename &patch_file, const Filename &orig_file,
const Filename &target_file) {
if (_initiated) {
express_cat.error()
<< "Patchfile::initiate() - Patching has already been initiated"
<< endl;
return EU_error_abort;
}
nassertr(orig_file != target_file, EU_error_abort);
VirtualFileSystem *vfs = VirtualFileSystem::get_global_ptr();
// Open the original file for read
nassertr(_origfile_stream == nullptr, EU_error_abort);
_orig_file = orig_file;
_orig_file.set_binary();
_origfile_stream = vfs->open_read_file(_orig_file, false);
if (_origfile_stream == nullptr) {
express_cat.error()
<< "Patchfile::initiate() - Failed to open file: " << _orig_file << endl;
return get_write_error();
}
// Open the temp file for write
_output_file = target_file;
_output_file.set_binary();
if (!_output_file.open_write(_write_stream)) {
express_cat.error()
<< "Patchfile::initiate() - Failed to open file: " << _output_file << endl;
return get_write_error();
}
if (express_cat.is_debug()) {
express_cat.debug()
<< "Patchfile using output file " << _output_file << "\n";
}
int result = internal_read_header(patch_file);
_total_bytes_processed = 0;
_initiated = true;
return result;
}
/**
* Opens the patch file for reading, and gets the header information from the
* file but does not begin to do any real work. This can be used to query the
* data stored in the patch.
*/
int Patchfile::
read_header(const Filename &patch_file) {
if (_initiated) {
express_cat.error()
<< "Patchfile::initiate() - Patching has already been initiated"
<< endl;
return EU_error_abort;
}
int result = internal_read_header(patch_file);
if (_patch_stream != nullptr) {
VirtualFileSystem *vfs = VirtualFileSystem::get_global_ptr();
vfs->close_read_file(_patch_stream);
_patch_stream = nullptr;
}
return result;
}
/**
* Perform one buffer's worth of patching Returns EU_ok while patching Returns
* EU_success when done If error happens will return one of: EU_error_abort :
* Patching has not been initiated EU_error_file_invalid : file is corrupted
* EU_error_invalid_checksum : incompatible patch file
* EU_error_write_file_rename : could not rename file
*/
int Patchfile::
run() {
// Now patch the file using the given buffer
int buflen;
int bytes_read;
uint16_t ADD_length;
uint16_t COPY_length;
int32_t COPY_offset;
if (_initiated == false) {
express_cat.error()
<< "Patchfile::run() - Patching has not been initiated"
<< endl;
return EU_error_abort;
}
nassertr(_patch_stream != nullptr, EU_error_abort);
nassertr(_origfile_stream != nullptr, EU_error_abort);
StreamReader patch_reader(*_patch_stream);
buflen = _buffer->get_length();
bytes_read = 0;
while (bytes_read < buflen) {
// read # of ADD bytes
nassertr(_buffer->get_length() >= (int)sizeof(ADD_length), false);
ADD_length = patch_reader.get_uint16();
if (_patch_stream->fail()) {
express_cat.error()
<< "Truncated patch file.\n";
return EU_error_file_invalid;
}
bytes_read += (int)ADD_length;
_total_bytes_processed += (int)ADD_length;
if (_total_bytes_processed > _total_bytes_to_process) {
express_cat.error()
<< "Runaway patch file.\n";
return EU_error_file_invalid;
}
// if there are bytes to add, read them from patch file and write them to
// output
if (express_cat.is_spam() && ADD_length != 0) {
express_cat.spam()
<< "ADD: " << ADD_length << " (to "
<< _write_stream.tellp() << ")" << endl;
}
uint32_t bytes_left = (uint32_t)ADD_length;
while (bytes_left > 0) {
uint32_t bytes_this_time = (uint32_t) min(bytes_left, (uint32_t) buflen);
_patch_stream->read(_buffer->_buffer, bytes_this_time);
if (_patch_stream->fail()) {
express_cat.error()
<< "Truncated patch file.\n";
return EU_error_file_invalid;
}
_write_stream.write(_buffer->_buffer, bytes_this_time);
bytes_left -= bytes_this_time;
}
// read # of COPY bytes
nassertr(_buffer->get_length() >= (int)sizeof(COPY_length), false);
COPY_length = patch_reader.get_uint16();
if (_patch_stream->fail()) {
express_cat.error()
<< "Truncated patch file.\n";
return EU_error_file_invalid;
}
bytes_read += (int)COPY_length;
_total_bytes_processed += (int)COPY_length;
if (_total_bytes_processed > _total_bytes_to_process) {
express_cat.error()
<< "Runaway patch file.\n";
return EU_error_file_invalid;
}
// if there are bytes to copy, read them from original file and write them
// to output
if (0 != COPY_length) {
// read copy offset
nassertr(_buffer->get_length() >= (int)sizeof(COPY_offset), false);
COPY_offset = patch_reader.get_int32();
if (_patch_stream->fail()) {
express_cat.error()
<< "Truncated patch file.\n";
return EU_error_file_invalid;
}
// seek to the copy source pos
if (_version_number < 2) {
_origfile_stream->seekg(COPY_offset, ios::beg);
} else {
_origfile_stream->seekg(COPY_offset, ios::cur);
}
if (_origfile_stream->fail()) {
express_cat.error()
<< "Invalid copy offset in patch file.\n";
return EU_error_file_invalid;
}
if (express_cat.is_spam()) {
express_cat.spam()
<< "COPY: " << COPY_length << " bytes from offset "
<< COPY_offset << " (from " << _origfile_stream->tellg()
<< " to " << _write_stream.tellp() << ")"
<< endl;
}
// read the copy bytes from original file and write them to output
uint32_t bytes_left = (uint32_t)COPY_length;
while (bytes_left > 0) {
uint32_t bytes_this_time = (uint32_t) min(bytes_left, (uint32_t) buflen);
_origfile_stream->read(_buffer->_buffer, bytes_this_time);
if (_origfile_stream->fail()) {
express_cat.error()
<< "Invalid copy length in patch file.\n";
return EU_error_file_invalid;
}
_write_stream.write(_buffer->_buffer, bytes_this_time);
bytes_left -= bytes_this_time;
}
}
// if we got a pair of zero-length ADD and COPY blocks, we're done
if ((0 == ADD_length) && (0 == COPY_length)) {
cleanup();
if (express_cat.is_debug()) {
express_cat.debug()
// << "result file = " << _result_file_length
<< " total bytes = " << _total_bytes_processed << endl;
}
// check the MD5 from the patch file against the newly patched file
{
HashVal MD5_actual;
MD5_actual.hash_file(_output_file);
if (_MD5_ofResult != MD5_actual) {
// Whoops, patching screwed up somehow.
if (_origfile_stream != nullptr) {
VirtualFileSystem *vfs = VirtualFileSystem::get_global_ptr();
vfs->close_read_file(_origfile_stream);
_origfile_stream = nullptr;
}
_write_stream.close();
express_cat.info()
<< "Patching produced incorrect checksum. Got:\n"
<< " " << MD5_actual
<< "\nExpected:\n"
<< " " << _MD5_ofResult
<< "\n";
// This is a fine time to double-check the starting checksum.
if (!has_source_hash()) {
express_cat.info()
<< "No source hash in patch file to verify.\n";
} else {
HashVal MD5_orig;
MD5_orig.hash_file(_orig_file);
if (MD5_orig != get_source_hash()) {
express_cat.info()
<< "Started from incorrect source file. Got:\n"
<< " " << MD5_orig
<< "\nExpected:\n"
<< " " << get_source_hash()
<< "\n";
} else {
express_cat.info()
<< "Started from correct source file:\n"
<< " " << MD5_orig
<< "\n";
}
}
// delete the temp file and the patch file
if (_rename_output_to_orig) {
_output_file.unlink();
}
if (_delete_patchfile) {
_patch_file.unlink();
}
// return "invalid checksum"
return EU_error_invalid_checksum;
}
}
// delete the patch file
if (_delete_patchfile) {
_patch_file.unlink();
}
// rename the temp file to the original file name
if (_rename_output_to_orig) {
_orig_file.unlink();
if (!_output_file.rename_to(_orig_file)) {
express_cat.error()
<< "Patchfile::run() failed to rename temp file to: " << _orig_file
<< endl;
return EU_error_write_file_rename;
}
}
return EU_success;
}
}
return EU_ok;
}
/**
* Patches the entire file in one call returns true on success and false on
* error
*
* This version will delete the patch file and overwrite the original file.
*/
bool Patchfile::
apply(Filename &patch_file, Filename &file) {
int ret = initiate(patch_file, file);
if (ret < 0)
return false;
for (;;) {
ret = run();
if (ret == EU_success)
return true;
if (ret < 0)
return false;
}
return false;
}
/**
* Patches the entire file in one call returns true on success and false on
* error
*
* This version will not delete any files.
*/
bool Patchfile::
apply(Filename &patch_file, Filename &orig_file, const Filename &target_file) {
int ret = initiate(patch_file, orig_file, target_file);
if (ret < 0)
return false;
for (;;) {
ret = run();
if (ret == EU_success)
return true;
if (ret < 0)
return false;
}
return false;
}
/**
* Reads the header and leaves the patch file open.
*/
int Patchfile::
internal_read_header(const Filename &patch_file) {
// Open the patch file for read
VirtualFileSystem *vfs = VirtualFileSystem::get_global_ptr();
nassertr(_patch_stream == nullptr, EU_error_abort);
_patch_file = patch_file;
_patch_file.set_binary();
_patch_stream = vfs->open_read_file(_patch_file, true);
if (_patch_stream == nullptr) {
express_cat.error()
<< "Patchfile::initiate() - Failed to open file: " << _patch_file << endl;
return get_write_error();
}
// read header, make sure the patch file is valid
StreamReader patch_reader(*_patch_stream);
// check the magic number
nassertr(_buffer->get_length() >= _v0_header_length, false);
uint32_t magic_number = patch_reader.get_uint32();
if (magic_number != _magic_number && magic_number != _v0_magic_number) {
express_cat.error()
<< "Invalid patch file: " << _patch_file << endl;
return EU_error_file_invalid;
}
_version_number = 0;
if (magic_number != _v0_magic_number) {
_version_number = patch_reader.get_uint16();
}
if (_version_number > _current_version) {
express_cat.error()
<< "Can't read version " << _version_number << " patch files: "
<< _patch_file << endl;
return EU_error_file_invalid;
}
if (_version_number >= 1) {
// Get the length of the source file.
/*uint32_t source_file_length =*/ patch_reader.get_uint32();
// get the MD5 of the source file.
_MD5_ofSource.read_stream(patch_reader);
}
// get the length of the patched result file
_total_bytes_to_process = patch_reader.get_uint32();
// get the MD5 of the resultant patched file
_MD5_ofResult.read_stream(patch_reader);
if (express_cat.is_debug()) {
express_cat.debug()
<< "Patchfile::initiate() - valid patchfile" << endl;
}
return EU_success;
}
// PATCH FILE BUILDING MEMBER FUNCTIONS
/**
*
*/
uint32_t Patchfile::
calc_hash(const char *buffer) {
#ifdef USE_MD5_FOR_HASHTABLE_INDEX_VALUES
HashVal hash;
hash.hash_buffer(buffer, _footprint_length);
// cout << uint16_t(hash.get_value(0)) << " ";
return uint16_t(hash.get_value(0));
#else
uint32_t hash_value = 0;
for(int i = 0; i < (int)_footprint_length; i++) {
// this is probably not such a good hash. to be replaced --> TRIED MD5,
// was not worth it for the execution-time hit on 800Mhz PC
hash_value ^= uint32_t(*buffer) << ((i * 2) % Patchfile::_HASH_BITS);
buffer++;
}
// use the bits that overflowed past the end of the hash bit range (this is
// intended for _HASH_BITS == 24)
hash_value ^= (hash_value >> Patchfile::_HASH_BITS);
// cout << hash_value << " ";
return hash_value & _HASH_MASK;
#endif
}
/**
*
* The hash and link tables allow for a quick, linear search of all locations
* in the file that begin with a particular sequence of bytes, or "footprint."
*
* The hash table is a table of offsets into the file, with one entry for
* every possible footprint hash value. For a hash of a footprint, the entry
* at the offset of the hash value provides an initial location in the file
* that has a matching footprint.
*
* The link table is a large linked list of file offsets, with one entry for
* every byte in the file. Each offset in the link table will point to
* another offset that has the same footprint at the corresponding offset in
* the actual file. Starting with an offset taken from the hash table, one
* can rapidly produce a list of offsets that all have the same footprint.
*/
void Patchfile::
build_hash_link_tables(const char *buffer_orig, uint32_t length_orig,
uint32_t *hash_table, uint32_t *link_table) {
uint32_t i;
// clear hash table
for(i = 0; i < _HASHTABLESIZE; i++) {
hash_table[i] = _NULL_VALUE;
}
// clear link table
for(i = 0; i < length_orig; i++) {
link_table[i] = _NULL_VALUE;
}
if(length_orig < _footprint_length) return;
// run through original file and hash each footprint
for(i = 0; i < (length_orig - _footprint_length); i++) {
uint32_t hash_value = calc_hash(&buffer_orig[i]);
// we must now store this file index in the hash table at the offset of
// the hash value
// to account for multiple file offsets with identical hash values, there
// is a link table with an entry for every footprint in the file. We
// create linked lists of offsets in the link table.
// first, set the value in the link table for the current offset to
// whatever the current list head is (the value in the hash table) (note
// that this only works because the hash and link tables both use
// _NULL_VALUE to indicate a null index)
link_table[i] = hash_table[hash_value];
// set the new list head; store the current offset in the hash table at
// the offset of the footprint's hash value
hash_table[hash_value] = i;
/*
if (_NULL_VALUE == hash_table[hash_value]) {
// hash entry is empty, store this offset
hash_table[hash_value] = i;
} else {
// hash entry is taken, go to the link table
uint32_t link_offset = hash_table[hash_value];
while (_NULL_VALUE != link_table[link_offset]) {
link_offset = link_table[link_offset];
}
link_table[link_offset] = i;
}
*/
}
}
/**
*
* This function calculates the length of a match between two strings of bytes
*/
uint32_t Patchfile::
calc_match_length(const char* buf1, const char* buf2, uint32_t max_length,
uint32_t min_length) {
// early out: look ahead and sample the end of the minimum range
if (min_length > 2) {
if (min_length >= max_length)
return 0;
if (buf1[min_length] != buf2[min_length] ||
buf1[min_length-1] != buf2[min_length-1] ||
buf1[min_length-2] != buf2[min_length-2]) {
return 0;
}
}
uint32_t length = 0;
while ((length < max_length) && (*buf1 == *buf2)) {
buf1++, buf2++, length++;
}
return length;
}
/**
*
* This function will find the longest string in the original file that
* matches a string in the new file.
*/
void Patchfile::
find_longest_match(uint32_t new_pos, uint32_t &copy_pos, uint16_t &copy_length,
uint32_t *hash_table, uint32_t *link_table, const char* buffer_orig,
uint32_t length_orig, const char* buffer_new, uint32_t length_new) {
// set length to a safe value
copy_length = 0;
// get offset of matching string (in orig file) from hash table
uint32_t hash_value = calc_hash(&buffer_new[new_pos]);
// if no match, bail
if (_NULL_VALUE == hash_table[hash_value])
return;
copy_pos = hash_table[hash_value];
// calc match length
copy_length = (uint16_t)calc_match_length(&buffer_new[new_pos],
&buffer_orig[copy_pos],
min(min((length_new - new_pos),
(length_orig - copy_pos)),
_MAX_RUN_LENGTH),
0);
// run through link table, see if we find any longer matches
uint32_t match_offset;
uint16_t match_length;
match_offset = link_table[copy_pos];
while (match_offset != _NULL_VALUE) {
match_length = (uint16_t)calc_match_length(&buffer_new[new_pos],
&buffer_orig[match_offset],
min(min((length_new - new_pos),
(length_orig - match_offset)),
_MAX_RUN_LENGTH),
copy_length);
// have we found a longer match?
if (match_length > copy_length) {
copy_pos = match_offset;
copy_length = match_length;
}
// traverse the link table
match_offset = link_table[match_offset];
}
}
/**
*
*/
void Patchfile::
emit_ADD(ostream &write_stream, uint32_t length, const char* buffer) {
nassertv(length == (uint16_t)length); //we only write a uint16
if (express_cat.is_spam()) {
express_cat.spam()
<< "ADD: " << length << " (to " << _add_pos << ")" << endl;
}
// write ADD length
StreamWriter patch_writer(write_stream);
patch_writer.add_uint16((uint16_t)length);
// if there are bytes to add, add them
if (length > 0) {
patch_writer.append_data(buffer, (uint16_t)length);
}
_add_pos += length;
}
/**
*
*/
void Patchfile::
emit_COPY(ostream &write_stream, uint32_t length, uint32_t copy_pos) {
nassertv(length == (uint16_t)length); //we only write a uint16
int32_t offset = (int)copy_pos - (int)_last_copy_pos;
if (express_cat.is_spam()) {
express_cat.spam()
<< "COPY: " << length << " bytes from offset " << offset
<< " (from " << copy_pos << " to " << _add_pos << ")" << endl;
}
// write COPY length
StreamWriter patch_writer(write_stream);
patch_writer.add_uint16((uint16_t)length);
if ((uint16_t)length != 0) {
// write COPY offset
patch_writer.add_int32(offset);
_last_copy_pos = copy_pos + length;
}
_add_pos += length;
}
/**
* Emits an add/copy pair. If necessary, repeats the pair as needed to work
* around the 16-bit chunk size limit.
*/
void Patchfile::
emit_add_and_copy(ostream &write_stream,
uint32_t add_length, const char *add_buffer,
uint32_t copy_length, uint32_t copy_pos) {
if (add_length == 0 && copy_length == 0) {
// Don't accidentally emit a termination code.
return;
}
static const uint16_t max_write = 65535;
while (add_length > max_write) {
// Overflow. This chunk is too large to fit into a single ADD block, so
// we have to write it as multiple ADDs.
emit_ADD(write_stream, max_write, add_buffer);
add_buffer += max_write;
add_length -= max_write;
emit_COPY(write_stream, 0, 0);
}
emit_ADD(write_stream, add_length, add_buffer);
while (copy_length > max_write) {
// Overflow.
emit_COPY(write_stream, max_write, copy_pos);
copy_pos += max_write;
copy_length -= max_write;
emit_ADD(write_stream, 0, nullptr);
}
emit_COPY(write_stream, copy_length, copy_pos);
}
/**
* Potentially emits one or more add/copy pairs. The current state is saved,
* so as to minimize wasted emits from consecutive adds or copies.
*/
void Patchfile::
cache_add_and_copy(ostream &write_stream,
uint32_t add_length, const char *add_buffer,
uint32_t copy_length, uint32_t copy_pos) {
if (add_length != 0) {
if (_cache_copy_length != 0) {
// Have to flush.
cache_flush(write_stream);
}
// Add the string to the current cache.
_cache_add_data += string(add_buffer, add_length);
}
if (copy_length != 0) {
if (_cache_copy_length == 0) {
// Start a new copy phase.
_cache_copy_start = copy_pos;
_cache_copy_length = copy_length;
} else if (_cache_copy_start + _cache_copy_length == copy_pos) {
// We can just tack on the copy to what we've already got.
_cache_copy_length += copy_length;
} else {
// It's a discontinuous copy. We have to flush.
cache_flush(write_stream);
_cache_copy_start = copy_pos;
_cache_copy_length = copy_length;
}
}
}
/**
* Closes any copy or add phases that are still open after a previous call to
* cache_add_and_copy().
*/
void Patchfile::
cache_flush(ostream &write_stream) {
emit_add_and_copy(write_stream,
_cache_add_data.size(), _cache_add_data.data(),
_cache_copy_length, _cache_copy_start);
_cache_add_data = string();
_cache_copy_length = 0;
}
/**
*
* Writes the patchfile header.
*/
void Patchfile::
write_header(ostream &write_stream,
istream &stream_orig, istream &stream_new) {
// prepare to write the patch file header
// write the patch file header
StreamWriter patch_writer(write_stream);
patch_writer.add_uint32(_magic_number);
patch_writer.add_uint16(_current_version);
stream_orig.seekg(0, ios::end);
streampos source_file_length = stream_orig.tellg();
patch_writer.add_uint32((uint32_t)source_file_length);
// calc MD5 of original file
_MD5_ofSource.hash_stream(stream_orig);
// add it to the header
_MD5_ofSource.write_stream(patch_writer);
if (express_cat.is_debug()) {
express_cat.debug()
<< "Orig: " << _MD5_ofSource << "\n";
}
stream_new.seekg(0, ios::end);
streampos result_file_length = stream_new.tellg();
patch_writer.add_uint32((uint32_t)result_file_length);
// calc MD5 of resultant patched file
_MD5_ofResult.hash_stream(stream_new);
// add it to the header
_MD5_ofResult.write_stream(patch_writer);
if (express_cat.is_debug()) {
express_cat.debug()
<< " New: " << _MD5_ofResult << "\n";
}
}
/**
* Writes the patchfile terminator.
*/
void Patchfile::
write_terminator(ostream &write_stream) {
cache_flush(write_stream);
// write terminator (null ADD, null COPY)
emit_ADD(write_stream, 0, nullptr);
emit_COPY(write_stream, 0, 0);
}
/**
* Computes the patches for the entire file (if it is not a multifile) or for
* a single subfile (if it is)
*
* Returns true if successful, false on error.
*/
bool Patchfile::
compute_file_patches(ostream &write_stream,
uint32_t offset_orig, uint32_t offset_new,
istream &stream_orig, istream &stream_new) {
// read in original file
stream_orig.seekg(0, ios::end);
nassertr(stream_orig, false);
uint32_t source_file_length = stream_orig.tellg();
if (express_cat.is_debug()) {
express_cat.debug()
<< "Allocating " << source_file_length << " bytes to read orig\n";
}
char *buffer_orig = (char *)PANDA_MALLOC_ARRAY(source_file_length);
stream_orig.seekg(0, ios::beg);
stream_orig.read(buffer_orig, source_file_length);
// read in new file
stream_new.seekg(0, ios::end);
uint32_t result_file_length = stream_new.tellg();
nassertr(stream_new, false);
if (express_cat.is_debug()) {
express_cat.debug()
<< "Allocating " << result_file_length << " bytes to read new\n";
}
char *buffer_new = (char *)PANDA_MALLOC_ARRAY(result_file_length);
stream_new.seekg(0, ios::beg);
stream_new.read(buffer_new, result_file_length);
// allocate hashlink tables
if (_hash_table == nullptr) {
if (express_cat.is_debug()) {
express_cat.debug()
<< "Allocating hashtable of size " << _HASHTABLESIZE << " * 4\n";
}
_hash_table = (uint32_t *)PANDA_MALLOC_ARRAY(_HASHTABLESIZE * sizeof(uint32_t));
}
if (express_cat.is_debug()) {
express_cat.debug()
<< "Allocating linktable of size " << source_file_length << " * 4\n";
}
uint32_t *link_table = (uint32_t *)PANDA_MALLOC_ARRAY(source_file_length * sizeof(uint32_t));
// build hash and link tables for original file
build_hash_link_tables(buffer_orig, source_file_length, _hash_table, link_table);
// run through new file
uint32_t new_pos = 0;
uint32_t start_pos = new_pos; // this is the position for the start of ADD operations
if(((uint32_t) result_file_length) >= _footprint_length)
{
while (new_pos < (result_file_length - _footprint_length)) {
// find best match for current position
uint32_t COPY_pos;
uint16_t COPY_length;
find_longest_match(new_pos, COPY_pos, COPY_length, _hash_table, link_table,
buffer_orig, source_file_length, buffer_new, result_file_length);
// if no match or match not longer than footprint length, skip to next
// byte
if (COPY_length < _footprint_length) {
// go to next byte
new_pos++;
} else {
// emit ADD for all skipped bytes
int num_skipped = (int)new_pos - (int)start_pos;
if (express_cat.is_spam()) {
express_cat.spam()
<< "build: num_skipped = " << num_skipped
<< endl;
}
cache_add_and_copy(write_stream, num_skipped, &buffer_new[start_pos],
COPY_length, COPY_pos + offset_orig);
new_pos += (uint32_t)COPY_length;
start_pos = new_pos;
}
}
}
if (express_cat.is_spam()) {
express_cat.spam()
<< "build: result_file_length = " << result_file_length
<< " start_pos = " << start_pos
<< endl;
}
// are there still more bytes left in the new file?
if (start_pos != result_file_length) {
// emit ADD for all remaining bytes
uint32_t remaining_bytes = result_file_length - start_pos;
cache_add_and_copy(write_stream, remaining_bytes, &buffer_new[start_pos],
0, 0);
start_pos += remaining_bytes;
}
PANDA_FREE_ARRAY(link_table);
PANDA_FREE_ARRAY(buffer_orig);
PANDA_FREE_ARRAY(buffer_new);
return true;
}
/**
* Computes patches for the files, knowing that they are both Panda
* Multifiles. This will build patches one subfile at a time, which can
* potentially be much, much faster for large Multifiles that contain many
* small subfiles.
*/
bool Patchfile::
compute_mf_patches(ostream &write_stream,
uint32_t offset_orig, uint32_t offset_new,
istream &stream_orig, istream &stream_new) {
Multifile mf_orig, mf_new;
IStreamWrapper stream_origw(stream_orig);
IStreamWrapper stream_neww(stream_new);
if (!mf_orig.open_read(&stream_origw) ||
!mf_new.open_read(&stream_neww)) {
express_cat.error()
<< "Input multifiles appear to be corrupt.\n";
return false;
}
if (mf_new.needs_repack()) {
express_cat.error()
<< "Input multifiles need to be repacked.\n";
return false;
}
// First, compute the patch for the header index.
{
ISubStream index_orig(&stream_origw, 0, mf_orig.get_index_end());
ISubStream index_new(&stream_neww, 0, mf_new.get_index_end());
if (!do_compute_patches("", "",
write_stream, offset_orig, offset_new,
index_orig, index_new)) {
return false;
}
nassertr(_add_pos + _cache_add_data.size() + _cache_copy_length == offset_new + (uint32_t)mf_new.get_index_end(), false);
}
// Now walk through each subfile in the new multifile. If a particular
// subfile exists in both source files, we compute the patches for the
// subfile; for a new subfile, we trivially add it. If a subfile has been
// removed, we simply don't add it (we'll never even notice this case).
int new_num_subfiles = mf_new.get_num_subfiles();
for (int ni = 0; ni < new_num_subfiles; ++ni) {
nassertr(_add_pos + _cache_add_data.size() + _cache_copy_length == offset_new + (uint32_t)mf_new.get_subfile_internal_start(ni), false);
string name = mf_new.get_subfile_name(ni);
int oi = mf_orig.find_subfile(name);
if (oi < 0) {
// This is a newly-added subfile. Add it the hard way.
express_cat.info()
<< "Adding subfile " << mf_new.get_subfile_name(ni) << "\n";
streampos new_start = mf_new.get_subfile_internal_start(ni);
size_t new_size = mf_new.get_subfile_internal_length(ni);
char *buffer_new = (char *)PANDA_MALLOC_ARRAY(new_size);
stream_new.seekg(new_start, ios::beg);
stream_new.read(buffer_new, new_size);
cache_add_and_copy(write_stream, new_size, buffer_new, 0, 0);
PANDA_FREE_ARRAY(buffer_new);
} else {
// This subfile exists in both the original and the new files. Patch
// it.
streampos orig_start = mf_orig.get_subfile_internal_start(oi);
size_t orig_size = mf_orig.get_subfile_internal_length(oi);
streampos new_start = mf_new.get_subfile_internal_start(ni);
size_t new_size = mf_new.get_subfile_internal_length(ni);
if (!patch_subfile(write_stream, offset_orig, offset_new,
mf_new.get_subfile_name(ni),
stream_origw, orig_start, orig_start + (streampos)orig_size,
stream_neww, new_start, new_start + (streampos)new_size)) {
return false;
}
}
}
return true;
}
#ifdef HAVE_TAR
/**
* Uses libtar to extract the location within the tar file of each of the
* subfiles. Returns true if the tar file is read successfully, false if
* there is an error (e.g. it is not a tar file).
*/
bool Patchfile::
read_tar(TarDef &tar, istream &stream) {
TAR *tfile;
tartype_t tt;
tt.openfunc = tar_openfunc;
tt.closefunc = tar_closefunc;
tt.readfunc = tar_readfunc;
tt.writefunc = tar_writefunc;
stream.seekg(0, ios::beg);
nassertr(_tar_istream == nullptr, false);
_tar_istream = &stream;
if (tar_open(&tfile, (char *)"dummy", &tt, O_RDONLY, 0, 0) != 0) {
_tar_istream = nullptr;
return false;
}
// Walk through the tar file, noting the current file position as we reach
// each subfile. Use this information to infer the start and end of each
// subfile within the stream.
streampos last_pos = 0;
int flag = th_read(tfile);
while (flag == 0) {
TarSubfile subfile;
subfile._name = th_get_pathname(tfile);
subfile._header_start = last_pos;
subfile._data_start = stream.tellg();
subfile._data_end = subfile._data_start + (streampos)th_get_size(tfile);
tar_skip_regfile(tfile);
subfile._end = stream.tellg();
tar.push_back(subfile);
last_pos = subfile._end;
flag = th_read(tfile);
}
// Create one more "subfile" for the bytes at the tail of the file. This
// subfile has no name.
TarSubfile subfile;
subfile._header_start = last_pos;
stream.clear();
stream.seekg(0, ios::end);
subfile._data_start = stream.tellg();
subfile._data_end = subfile._data_start;
subfile._end = subfile._data_start;
tar.push_back(subfile);
tar_close(tfile);
_tar_istream = nullptr;
return (flag == 1);
}
#endif // HAVE_TAR
#ifdef HAVE_TAR
/**
* Computes patches for the files, knowing that they are both tar files. This
* is similar to compute_mf_patches().
*
* The tar indexes should have been built up by a previous call to read_tar().
*/
bool Patchfile::
compute_tar_patches(ostream &write_stream,
uint32_t offset_orig, uint32_t offset_new,
istream &stream_orig, istream &stream_new,
TarDef &tar_orig, TarDef &tar_new) {
// Sort the orig list by filename, so we can quickly look up files from the
// new list.
tar_orig.sort();
// However, it is important to keep the new list in its original, on-disk
// order.
// Walk through each subfile in the new tar file. If a particular subfile
// exists in both source files, we compute the patches for the subfile; for
// a new subfile, we trivially add it. If a subfile has been removed, we
// simply don't add it (we'll never even notice this case).
IStreamWrapper stream_origw(stream_orig);
IStreamWrapper stream_neww(stream_new);
TarDef::const_iterator ni;
streampos last_pos = 0;
for (ni = tar_new.begin(); ni != tar_new.end(); ++ni) {
const TarSubfile &sf_new =(*ni);
nassertr(sf_new._header_start == last_pos, false);
TarDef::const_iterator oi = tar_orig.find(sf_new);
if (oi == tar_orig.end()) {
// This is a newly-added subfile. Add it the hard way.
express_cat.info()
<< "Adding subfile " << sf_new._name << "\n";
streampos new_start = sf_new._header_start;
size_t new_size = sf_new._end - sf_new._header_start;
char *buffer_new = (char *)PANDA_MALLOC_ARRAY(new_size);
stream_new.seekg(new_start, ios::beg);
stream_new.read(buffer_new, new_size);
cache_add_and_copy(write_stream, new_size, buffer_new, 0, 0);
PANDA_FREE_ARRAY(buffer_new);
} else {
// This subfile exists in both the original and the new files. Patch
// it.
const TarSubfile &sf_orig =(*oi);
// We patch the header and data of the file separately, so we can
// accurately detect nested multifiles. The extra data at the end of
// the file (possibly introduced by a tar file's blocking) is the
// footer, which is also patched separately.
if (!patch_subfile(write_stream, offset_orig, offset_new, "",
stream_origw, sf_orig._header_start, sf_orig._data_start,
stream_neww, sf_new._header_start, sf_new._data_start)) {
return false;
}
if (!patch_subfile(write_stream, offset_orig, offset_new, sf_new._name,
stream_origw, sf_orig._data_start, sf_orig._data_end,
stream_neww, sf_new._data_start, sf_new._data_end)) {
return false;
}
if (!patch_subfile(write_stream, offset_orig, offset_new, "",
stream_origw, sf_orig._data_end, sf_orig._end,
stream_neww, sf_new._data_end, sf_new._end)) {
return false;
}
}
last_pos = sf_new._end;
}
return true;
}
#endif // HAVE_TAR
#ifdef HAVE_TAR
/**
* A callback function to redirect libtar to read from our istream instead of
* using low-level Unix I/O.
*/
int Patchfile::
tar_openfunc(const char *, int, ...) {
// Since we don't actually open a file--the stream is already open--we do
// nothing here.
return 0;
}
#endif // HAVE_TAR
#ifdef HAVE_TAR
/**
* A callback function to redirect libtar to read from our istream instead of
* using low-level Unix I/O.
*/
int Patchfile::
tar_closefunc(int) {
// Since we don't actually open a file, no need to close it either.
return 0;
}
#endif // HAVE_TAR
#ifdef HAVE_TAR
/**
* A callback function to redirect libtar to read from our istream instead of
* using low-level Unix I/O.
*/
ssize_t Patchfile::
tar_readfunc(int, void *buffer, size_t nbytes) {
nassertr(_tar_istream != nullptr, 0);
_tar_istream->read((char *)buffer, nbytes);
return (ssize_t)_tar_istream->gcount();
}
#endif // HAVE_TAR
#ifdef HAVE_TAR
/**
* A callback function to redirect libtar to read from our istream instead of
* using low-level Unix I/O.
*/
ssize_t Patchfile::
tar_writefunc(int, const void *, size_t) {
// Since we use libtar only for reading, it is an error if this method gets
// called.
nassertr(false, -1);
return -1;
}
#endif // HAVE_TAR
/**
*
* This implementation uses the "greedy differencing algorithm" described in
* the masters thesis "Differential Compression: A Generalized Solution for
* Binary Files" by Randal C. Burns (p.13). For an original file of size M and
* a new file of size N, this algorithm is O(M) in space and O(M*N) (worst-
* case) in time. return false on error
*/
bool Patchfile::
build(Filename file_orig, Filename file_new, Filename patch_name) {
patch_name.set_binary();
// Open the original file for read
pifstream stream_orig;
file_orig.set_binary();
if (!file_orig.open_read(stream_orig)) {
express_cat.error()
<< "Patchfile::build() - Failed to open file: " << file_orig << endl;
return false;
}
// Open the new file for read
pifstream stream_new;
file_new.set_binary();
if (!file_new.open_read(stream_new)) {
express_cat.error()
<< "Patchfile::build() - Failed to open file: " << file_new << endl;
return false;
}
// Open patch file for write
pofstream write_stream;
if (!patch_name.open_write(write_stream)) {
express_cat.error()
<< "Patchfile::build() - Failed to open file: " << patch_name << endl;
return false;
}
_last_copy_pos = 0;
_add_pos = 0;
_cache_add_data = string();
_cache_copy_start = 0;
_cache_copy_length = 0;
write_header(write_stream, stream_orig, stream_new);
if (!do_compute_patches(file_orig, file_new,
write_stream, 0, 0,
stream_orig, stream_new)) {
return false;
}
write_terminator(write_stream);
if (express_cat.is_debug()) {
express_cat.debug()
<< "Patch file will generate " << _add_pos << "-byte file.\n";
}
#ifndef NDEBUG
{
// Make sure the resulting file would be the right size.
stream_new.seekg(0, ios::end);
streampos result_file_length = stream_new.tellg();
nassertr(_add_pos == result_file_length, false);
}
#endif // NDEBUG
return (_last_copy_pos != 0);
}
/**
* Computes the patches for the indicated A to B files, or subfiles. Checks
* for multifiles or tar files before falling back to whole-file patching.
*/
bool Patchfile::
do_compute_patches(const Filename &file_orig, const Filename &file_new,
ostream &write_stream,
uint32_t offset_orig, uint32_t offset_new,
istream &stream_orig, istream &stream_new) {
nassertr(_add_pos + _cache_add_data.size() + _cache_copy_length == offset_new, false);
// Check whether our input files are Panda multifiles or tar files.
bool is_multifile = false;
#ifdef HAVE_TAR
bool is_tarfile = false;
TarDef tar_orig, tar_new;
#endif // HAVE_TAR
if (_allow_multifile) {
if (strstr(file_orig.get_basename().c_str(), ".mf") != nullptr ||
strstr(file_new.get_basename().c_str(), ".mf") != nullptr) {
// Read the first n bytes of both files for the Multifile magic number.
string magic_number = Multifile::get_magic_number();
char *buffer = (char *)PANDA_MALLOC_ARRAY(magic_number.size());
stream_orig.seekg(0, ios::beg);
stream_orig.read(buffer, magic_number.size());
if (stream_orig.gcount() == (int)magic_number.size() &&
memcmp(buffer, magic_number.data(), magic_number.size()) == 0) {
stream_new.seekg(0, ios::beg);
stream_new.read(buffer, magic_number.size());
if (stream_new.gcount() == (int)magic_number.size() &&
memcmp(buffer, magic_number.data(), magic_number.size()) == 0) {
is_multifile = true;
}
}
PANDA_FREE_ARRAY(buffer);
}
#ifdef HAVE_TAR
if (strstr(file_orig.get_basename().c_str(), ".tar") != nullptr ||
strstr(file_new.get_basename().c_str(), ".tar") != nullptr) {
if (read_tar(tar_orig, stream_orig) &&
read_tar(tar_new, stream_new)) {
is_tarfile = true;
}
}
#endif // HAVE_TAR
}
if (is_multifile) {
if (express_cat.is_debug()) {
express_cat.debug()
<< file_orig.get_basename() << " appears to be a Panda Multifile.\n";
}
if (!compute_mf_patches(write_stream, offset_orig, offset_new,
stream_orig, stream_new)) {
return false;
}
#ifdef HAVE_TAR
} else if (is_tarfile) {
if (express_cat.is_debug()) {
express_cat.debug()
<< file_orig.get_basename() << " appears to be a tar file.\n";
}
if (!compute_tar_patches(write_stream, offset_orig, offset_new,
stream_orig, stream_new, tar_orig, tar_new)) {
return false;
}
#endif // HAVE_TAR
} else {
if (express_cat.is_debug()) {
express_cat.debug()
<< file_orig.get_basename() << " is not a multifile.\n";
}
if (!compute_file_patches(write_stream, offset_orig, offset_new,
stream_orig, stream_new)) {
return false;
}
}
return true;
}
/**
* Generates patches for a nested subfile of a Panda Multifile or a tar file.
*/
bool Patchfile::
patch_subfile(ostream &write_stream,
uint32_t offset_orig, uint32_t offset_new,
const Filename &filename,
IStreamWrapper &stream_orig, streampos orig_start, streampos orig_end,
IStreamWrapper &stream_new, streampos new_start, streampos new_end) {
nassertr(_add_pos + _cache_add_data.size() + _cache_copy_length == offset_new + (uint32_t)new_start, false);
size_t new_size = new_end - new_start;
size_t orig_size = orig_end - orig_start;
ISubStream subfile_orig(&stream_orig, orig_start, orig_end);
ISubStream subfile_new(&stream_new, new_start, new_end);
bool is_unchanged = false;
if (orig_size == new_size) {
HashVal hash_orig, hash_new;
hash_orig.hash_stream(subfile_orig);
hash_new.hash_stream(subfile_new);
if (hash_orig == hash_new) {
// Actually, the subfile is unchanged; just emit it.
is_unchanged = true;
}
}
if (is_unchanged) {
if (express_cat.is_debug() && !filename.empty()) {
express_cat.debug()
<< "Keeping subfile " << filename << "\n";
}
cache_add_and_copy(write_stream, 0, nullptr,
orig_size, offset_orig + orig_start);
} else {
if (!filename.empty()) {
express_cat.info()
<< "Patching subfile " << filename << "\n";
}
if (!do_compute_patches(filename, filename, write_stream,
offset_orig + orig_start, offset_new + new_start,
subfile_orig, subfile_new)) {
return false;
}
}
return true;
}
#endif // HAVE_OPENSSL
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