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/*
* Copyright 2009, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
//
// TarProcessor processes a tar byte stream (uncompressed).
#include "base/logging.h"
#include "import/cross/tar_processor.h"
namespace o3d {
static const int kFileSizeOffset = 124;
static const int kLinkFlagOffset = 156;
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
int TarProcessor::ProcessBytes(MemoryReadStream *stream, size_t n) {
// Keep processing the byte-stream until we've consumed all we're given
//
size_t bytes_to_consume = n;
while (bytes_to_consume > 0) {
// First see if we have any more header bytes to read
if (header_bytes_read_ < TAR_HEADER_SIZE) {
// Read header bytes
size_t header_bytes_remaining = TAR_HEADER_SIZE - header_bytes_read_;
size_t bytes_to_read = std::min(bytes_to_consume, header_bytes_remaining);
size_t bytes_read =
stream->Read(reinterpret_cast<uint8*>(header_ + header_bytes_read_),
bytes_to_read);
if (bytes_read != bytes_to_read) {
return -1;
}
header_bytes_read_ += bytes_to_read;
bytes_to_consume -= bytes_to_read;
if (header_bytes_read_ == TAR_HEADER_SIZE) {
// The tar format stupidly represents size_t values as octal strings!!
unsigned int file_size = 0u;
sscanf(header_ + kFileSizeOffset, "%o", &file_size);
// Check if it's a long filename
char type = header_[kLinkFlagOffset];
if (type == 'L') {
getting_filename_ = true;
// We should pick some size that's too large.
if (file_size > 1024) {
return -1;
}
} else {
getting_filename_ = false;
const char *filename = (const char *)header_;
if (!file_name_.empty()) {
filename = file_name_.c_str();
}
// Only callback client if this is a "real" header
// (filename is not NULL)
// Extra zero-padding can be added by the gzip compression
// (at end of archive), so ignore these ones.
//
// Also, ignore entries for directories (which have zero size)
if (header_[0] != 0 && file_size > 0) {
ArchiveFileInfo info(filename, file_size);
callback_client_->ReceiveFileHeader(info);
} else if (header_[0] == 0) {
// If filename is NULL due to zero-padding then file size
// should also be NULL
// TODO(gman): Won't this crash the plugin if I make a bad tar?
assert(file_size == 0);
}
}
// Round filesize up to nearest block size
file_bytes_to_read_ =
(file_size + TAR_BLOCK_SIZE - 1) & ~(TAR_BLOCK_SIZE - 1);
// Our client doesn't want to be bothered with the block padding,
// so only send him the actual file bytes
client_file_bytes_to_read_ = file_size;
// Clear the file_name_ so we don't use it next time.
file_name_.clear();
}
}
if (bytes_to_consume > 0) {
// Looks like we have some left-over bytes past the header
// -- size_terpret as file bytes
if (client_file_bytes_to_read_ > 0) {
// Callback to client with some file data
// Use a copy of the stream in case the client doesn't read
// the amount they're supposed to
MemoryReadStream client_read_stream(*stream);
size_t client_bytes_this_time =
std::min(bytes_to_consume, client_file_bytes_to_read_);
if (getting_filename_) {
String name_piece(
client_read_stream.GetDirectMemoryPointerAs<const char>(),
client_bytes_this_time);
client_read_stream.Skip(client_bytes_this_time);
file_name_ += name_piece;
} else {
if (!callback_client_->ReceiveFileData(&client_read_stream,
client_bytes_this_time)) {
return -1;
}
}
client_file_bytes_to_read_ -= client_bytes_this_time;
file_bytes_to_read_ -= client_bytes_this_time;
// Advance stream the amount the client should have consumed
stream->Skip(client_bytes_this_time);
bytes_to_consume -= client_bytes_this_time;
}
// Now, check if we have any padding bytes (up to block size)
// past the file data
if (bytes_to_consume > 0) {
size_t bytes_to_skip = std::min(bytes_to_consume, file_bytes_to_read_);
stream->Skip(bytes_to_skip);
file_bytes_to_read_ -= bytes_to_skip;
bytes_to_consume -= bytes_to_skip;
}
if (file_bytes_to_read_ == 0) {
// We've read all of the file data,
// so now expect the next file header
// setting to 0 makes us want more header bytes
header_bytes_read_ = 0;
}
}
}
return 0;
}
} // namespace o3d
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