/thirdparty/breakpad/third_party/protobuf/protobuf/src/google/protobuf/io/coded_stream.cc
http://github.com/tomahawk-player/tomahawk · C++ · 839 lines · 584 code · 115 blank · 140 comment · 164 complexity · d1b669963ae433a35dea887deab409e4 MD5 · raw file
- // Protocol Buffers - Google's data interchange format
- // Copyright 2008 Google Inc. All rights reserved.
- // http://code.google.com/p/protobuf/
- //
- // 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.
- // Author: kenton@google.com (Kenton Varda)
- // Based on original Protocol Buffers design by
- // Sanjay Ghemawat, Jeff Dean, and others.
- //
- // This implementation is heavily optimized to make reads and writes
- // of small values (especially varints) as fast as possible. In
- // particular, we optimize for the common case that a read or a write
- // will not cross the end of the buffer, since we can avoid a lot
- // of branching in this case.
- #include <google/protobuf/io/coded_stream_inl.h>
- #include <algorithm>
- #include <limits.h>
- #include <google/protobuf/io/zero_copy_stream.h>
- #include <google/protobuf/stubs/common.h>
- #include <google/protobuf/stubs/stl_util-inl.h>
- namespace google {
- namespace protobuf {
- namespace io {
- namespace {
- static const int kMaxVarintBytes = 10;
- static const int kMaxVarint32Bytes = 5;
- inline bool NextNonEmpty(ZeroCopyInputStream* input,
- const void** data, int* size) {
- bool success;
- do {
- success = input->Next(data, size);
- } while (success && *size == 0);
- return success;
- }
- } // namespace
- // CodedInputStream ==================================================
- void CodedInputStream::BackUpInputToCurrentPosition() {
- int backup_bytes = BufferSize() + buffer_size_after_limit_ + overflow_bytes_;
- if (backup_bytes > 0) {
- input_->BackUp(backup_bytes);
- // total_bytes_read_ doesn't include overflow_bytes_.
- total_bytes_read_ -= BufferSize() + buffer_size_after_limit_;
- buffer_end_ = buffer_;
- buffer_size_after_limit_ = 0;
- overflow_bytes_ = 0;
- }
- }
- inline void CodedInputStream::RecomputeBufferLimits() {
- buffer_end_ += buffer_size_after_limit_;
- int closest_limit = min(current_limit_, total_bytes_limit_);
- if (closest_limit < total_bytes_read_) {
- // The limit position is in the current buffer. We must adjust
- // the buffer size accordingly.
- buffer_size_after_limit_ = total_bytes_read_ - closest_limit;
- buffer_end_ -= buffer_size_after_limit_;
- } else {
- buffer_size_after_limit_ = 0;
- }
- }
- CodedInputStream::Limit CodedInputStream::PushLimit(int byte_limit) {
- // Current position relative to the beginning of the stream.
- int current_position = total_bytes_read_ -
- (BufferSize() + buffer_size_after_limit_);
- Limit old_limit = current_limit_;
- // security: byte_limit is possibly evil, so check for negative values
- // and overflow.
- if (byte_limit >= 0 &&
- byte_limit <= INT_MAX - current_position) {
- current_limit_ = current_position + byte_limit;
- } else {
- // Negative or overflow.
- current_limit_ = INT_MAX;
- }
- // We need to enforce all limits, not just the new one, so if the previous
- // limit was before the new requested limit, we continue to enforce the
- // previous limit.
- current_limit_ = min(current_limit_, old_limit);
- RecomputeBufferLimits();
- return old_limit;
- }
- void CodedInputStream::PopLimit(Limit limit) {
- // The limit passed in is actually the *old* limit, which we returned from
- // PushLimit().
- current_limit_ = limit;
- RecomputeBufferLimits();
- // We may no longer be at a legitimate message end. ReadTag() needs to be
- // called again to find out.
- legitimate_message_end_ = false;
- }
- int CodedInputStream::BytesUntilLimit() {
- if (current_limit_ == INT_MAX) return -1;
- int current_position = total_bytes_read_ -
- (BufferSize() + buffer_size_after_limit_);
- return current_limit_ - current_position;
- }
- void CodedInputStream::SetTotalBytesLimit(
- int total_bytes_limit, int warning_threshold) {
- // Make sure the limit isn't already past, since this could confuse other
- // code.
- int current_position = total_bytes_read_ -
- (BufferSize() + buffer_size_after_limit_);
- total_bytes_limit_ = max(current_position, total_bytes_limit);
- total_bytes_warning_threshold_ = warning_threshold;
- RecomputeBufferLimits();
- }
- void CodedInputStream::PrintTotalBytesLimitError() {
- GOOGLE_LOG(ERROR) << "A protocol message was rejected because it was too "
- "big (more than " << total_bytes_limit_
- << " bytes). To increase the limit (or to disable these "
- "warnings), see CodedInputStream::SetTotalBytesLimit() "
- "in google/protobuf/io/coded_stream.h.";
- }
- bool CodedInputStream::Skip(int count) {
- if (count < 0) return false; // security: count is often user-supplied
- const int original_buffer_size = BufferSize();
- if (count <= original_buffer_size) {
- // Just skipping within the current buffer. Easy.
- Advance(count);
- return true;
- }
- if (buffer_size_after_limit_ > 0) {
- // We hit a limit inside this buffer. Advance to the limit and fail.
- Advance(original_buffer_size);
- return false;
- }
- count -= original_buffer_size;
- buffer_ = NULL;
- buffer_end_ = buffer_;
- // Make sure this skip doesn't try to skip past the current limit.
- int closest_limit = min(current_limit_, total_bytes_limit_);
- int bytes_until_limit = closest_limit - total_bytes_read_;
- if (bytes_until_limit < count) {
- // We hit the limit. Skip up to it then fail.
- if (bytes_until_limit > 0) {
- total_bytes_read_ = closest_limit;
- input_->Skip(bytes_until_limit);
- }
- return false;
- }
- total_bytes_read_ += count;
- return input_->Skip(count);
- }
- bool CodedInputStream::GetDirectBufferPointer(const void** data, int* size) {
- if (BufferSize() == 0 && !Refresh()) return false;
- *data = buffer_;
- *size = BufferSize();
- return true;
- }
- bool CodedInputStream::ReadRaw(void* buffer, int size) {
- int current_buffer_size;
- while ((current_buffer_size = BufferSize()) < size) {
- // Reading past end of buffer. Copy what we have, then refresh.
- memcpy(buffer, buffer_, current_buffer_size);
- buffer = reinterpret_cast<uint8*>(buffer) + current_buffer_size;
- size -= current_buffer_size;
- Advance(current_buffer_size);
- if (!Refresh()) return false;
- }
- memcpy(buffer, buffer_, size);
- Advance(size);
- return true;
- }
- bool CodedInputStream::ReadString(string* buffer, int size) {
- if (size < 0) return false; // security: size is often user-supplied
- return InternalReadStringInline(buffer, size);
- }
- bool CodedInputStream::ReadStringFallback(string* buffer, int size) {
- if (!buffer->empty()) {
- buffer->clear();
- }
- int current_buffer_size;
- while ((current_buffer_size = BufferSize()) < size) {
- // Some STL implementations "helpfully" crash on buffer->append(NULL, 0).
- if (current_buffer_size != 0) {
- // Note: string1.append(string2) is O(string2.size()) (as opposed to
- // O(string1.size() + string2.size()), which would be bad).
- buffer->append(reinterpret_cast<const char*>(buffer_),
- current_buffer_size);
- }
- size -= current_buffer_size;
- Advance(current_buffer_size);
- if (!Refresh()) return false;
- }
- buffer->append(reinterpret_cast<const char*>(buffer_), size);
- Advance(size);
- return true;
- }
- bool CodedInputStream::ReadLittleEndian32Fallback(uint32* value) {
- uint8 bytes[sizeof(*value)];
- const uint8* ptr;
- if (BufferSize() >= sizeof(*value)) {
- // Fast path: Enough bytes in the buffer to read directly.
- ptr = buffer_;
- Advance(sizeof(*value));
- } else {
- // Slow path: Had to read past the end of the buffer.
- if (!ReadRaw(bytes, sizeof(*value))) return false;
- ptr = bytes;
- }
- ReadLittleEndian32FromArray(ptr, value);
- return true;
- }
- bool CodedInputStream::ReadLittleEndian64Fallback(uint64* value) {
- uint8 bytes[sizeof(*value)];
- const uint8* ptr;
- if (BufferSize() >= sizeof(*value)) {
- // Fast path: Enough bytes in the buffer to read directly.
- ptr = buffer_;
- Advance(sizeof(*value));
- } else {
- // Slow path: Had to read past the end of the buffer.
- if (!ReadRaw(bytes, sizeof(*value))) return false;
- ptr = bytes;
- }
- ReadLittleEndian64FromArray(ptr, value);
- return true;
- }
- namespace {
- inline const uint8* ReadVarint32FromArray(
- const uint8* buffer, uint32* value) GOOGLE_ATTRIBUTE_ALWAYS_INLINE;
- inline const uint8* ReadVarint32FromArray(const uint8* buffer, uint32* value) {
- // Fast path: We have enough bytes left in the buffer to guarantee that
- // this read won't cross the end, so we can skip the checks.
- const uint8* ptr = buffer;
- uint32 b;
- uint32 result;
- b = *(ptr++); result = (b & 0x7F) ; if (!(b & 0x80)) goto done;
- b = *(ptr++); result |= (b & 0x7F) << 7; if (!(b & 0x80)) goto done;
- b = *(ptr++); result |= (b & 0x7F) << 14; if (!(b & 0x80)) goto done;
- b = *(ptr++); result |= (b & 0x7F) << 21; if (!(b & 0x80)) goto done;
- b = *(ptr++); result |= b << 28; if (!(b & 0x80)) goto done;
- // If the input is larger than 32 bits, we still need to read it all
- // and discard the high-order bits.
- for (int i = 0; i < kMaxVarintBytes - kMaxVarint32Bytes; i++) {
- b = *(ptr++); if (!(b & 0x80)) goto done;
- }
- // We have overrun the maximum size of a varint (10 bytes). Assume
- // the data is corrupt.
- return NULL;
- done:
- *value = result;
- return ptr;
- }
- } // namespace
- bool CodedInputStream::ReadVarint32Slow(uint32* value) {
- uint64 result;
- // Directly invoke ReadVarint64Fallback, since we already tried to optimize
- // for one-byte varints.
- if (!ReadVarint64Fallback(&result)) return false;
- *value = (uint32)result;
- return true;
- }
- bool CodedInputStream::ReadVarint32Fallback(uint32* value) {
- if (BufferSize() >= kMaxVarintBytes ||
- // Optimization: If the varint ends at exactly the end of the buffer,
- // we can detect that and still use the fast path.
- (buffer_end_ > buffer_ && !(buffer_end_[-1] & 0x80))) {
- const uint8* end = ReadVarint32FromArray(buffer_, value);
- if (end == NULL) return false;
- buffer_ = end;
- return true;
- } else {
- // Really slow case: we will incur the cost of an extra function call here,
- // but moving this out of line reduces the size of this function, which
- // improves the common case. In micro benchmarks, this is worth about 10-15%
- return ReadVarint32Slow(value);
- }
- }
- uint32 CodedInputStream::ReadTagSlow() {
- if (buffer_ == buffer_end_) {
- // Call refresh.
- if (!Refresh()) {
- // Refresh failed. Make sure that it failed due to EOF, not because
- // we hit total_bytes_limit_, which, unlike normal limits, is not a
- // valid place to end a message.
- int current_position = total_bytes_read_ - buffer_size_after_limit_;
- if (current_position >= total_bytes_limit_) {
- // Hit total_bytes_limit_. But if we also hit the normal limit,
- // we're still OK.
- legitimate_message_end_ = current_limit_ == total_bytes_limit_;
- } else {
- legitimate_message_end_ = true;
- }
- return 0;
- }
- }
- // For the slow path, just do a 64-bit read. Try to optimize for one-byte tags
- // again, since we have now refreshed the buffer.
- uint64 result;
- if (!ReadVarint64(&result)) return 0;
- return static_cast<uint32>(result);
- }
- uint32 CodedInputStream::ReadTagFallback() {
- if (BufferSize() >= kMaxVarintBytes ||
- // Optimization: If the varint ends at exactly the end of the buffer,
- // we can detect that and still use the fast path.
- (buffer_end_ > buffer_ && !(buffer_end_[-1] & 0x80))) {
- uint32 tag;
- const uint8* end = ReadVarint32FromArray(buffer_, &tag);
- if (end == NULL) {
- return 0;
- }
- buffer_ = end;
- return tag;
- } else {
- // We are commonly at a limit when attempting to read tags. Try to quickly
- // detect this case without making another function call.
- if (buffer_ == buffer_end_ && buffer_size_after_limit_ > 0 &&
- // Make sure that the limit we hit is not total_bytes_limit_, since
- // in that case we still need to call Refresh() so that it prints an
- // error.
- total_bytes_read_ - buffer_size_after_limit_ < total_bytes_limit_) {
- // We hit a byte limit.
- legitimate_message_end_ = true;
- return 0;
- }
- return ReadTagSlow();
- }
- }
- bool CodedInputStream::ReadVarint64Slow(uint64* value) {
- // Slow path: This read might cross the end of the buffer, so we
- // need to check and refresh the buffer if and when it does.
- uint64 result = 0;
- int count = 0;
- uint32 b;
- do {
- if (count == kMaxVarintBytes) return false;
- while (buffer_ == buffer_end_) {
- if (!Refresh()) return false;
- }
- b = *buffer_;
- result |= static_cast<uint64>(b & 0x7F) << (7 * count);
- Advance(1);
- ++count;
- } while (b & 0x80);
- *value = result;
- return true;
- }
- bool CodedInputStream::ReadVarint64Fallback(uint64* value) {
- if (BufferSize() >= kMaxVarintBytes ||
- // Optimization: If the varint ends at exactly the end of the buffer,
- // we can detect that and still use the fast path.
- (buffer_end_ > buffer_ && !(buffer_end_[-1] & 0x80))) {
- // Fast path: We have enough bytes left in the buffer to guarantee that
- // this read won't cross the end, so we can skip the checks.
- const uint8* ptr = buffer_;
- uint32 b;
- // Splitting into 32-bit pieces gives better performance on 32-bit
- // processors.
- uint32 part0 = 0, part1 = 0, part2 = 0;
- b = *(ptr++); part0 = (b & 0x7F) ; if (!(b & 0x80)) goto done;
- b = *(ptr++); part0 |= (b & 0x7F) << 7; if (!(b & 0x80)) goto done;
- b = *(ptr++); part0 |= (b & 0x7F) << 14; if (!(b & 0x80)) goto done;
- b = *(ptr++); part0 |= (b & 0x7F) << 21; if (!(b & 0x80)) goto done;
- b = *(ptr++); part1 = (b & 0x7F) ; if (!(b & 0x80)) goto done;
- b = *(ptr++); part1 |= (b & 0x7F) << 7; if (!(b & 0x80)) goto done;
- b = *(ptr++); part1 |= (b & 0x7F) << 14; if (!(b & 0x80)) goto done;
- b = *(ptr++); part1 |= (b & 0x7F) << 21; if (!(b & 0x80)) goto done;
- b = *(ptr++); part2 = (b & 0x7F) ; if (!(b & 0x80)) goto done;
- b = *(ptr++); part2 |= (b & 0x7F) << 7; if (!(b & 0x80)) goto done;
- // We have overrun the maximum size of a varint (10 bytes). The data
- // must be corrupt.
- return NULL;
- done:
- Advance(ptr - buffer_);
- *value = (static_cast<uint64>(part0) ) |
- (static_cast<uint64>(part1) << 28) |
- (static_cast<uint64>(part2) << 56);
- return true;
- } else {
- return ReadVarint64Slow(value);
- }
- }
- bool CodedInputStream::Refresh() {
- GOOGLE_DCHECK_EQ(0, BufferSize());
- if (buffer_size_after_limit_ > 0 || overflow_bytes_ > 0 ||
- total_bytes_read_ == current_limit_) {
- // We've hit a limit. Stop.
- int current_position = total_bytes_read_ - buffer_size_after_limit_;
- if (current_position >= total_bytes_limit_ &&
- total_bytes_limit_ != current_limit_) {
- // Hit total_bytes_limit_.
- PrintTotalBytesLimitError();
- }
- return false;
- }
- if (total_bytes_warning_threshold_ >= 0 &&
- total_bytes_read_ >= total_bytes_warning_threshold_) {
- GOOGLE_LOG(WARNING) << "Reading dangerously large protocol message. If the "
- "message turns out to be larger than "
- << total_bytes_limit_ << " bytes, parsing will be halted "
- "for security reasons. To increase the limit (or to "
- "disable these warnings), see "
- "CodedInputStream::SetTotalBytesLimit() in "
- "google/protobuf/io/coded_stream.h.";
- // Don't warn again for this stream.
- total_bytes_warning_threshold_ = -1;
- }
- const void* void_buffer;
- int buffer_size;
- if (NextNonEmpty(input_, &void_buffer, &buffer_size)) {
- buffer_ = reinterpret_cast<const uint8*>(void_buffer);
- buffer_end_ = buffer_ + buffer_size;
- GOOGLE_CHECK_GE(buffer_size, 0);
- if (total_bytes_read_ <= INT_MAX - buffer_size) {
- total_bytes_read_ += buffer_size;
- } else {
- // Overflow. Reset buffer_end_ to not include the bytes beyond INT_MAX.
- // We can't get that far anyway, because total_bytes_limit_ is guaranteed
- // to be less than it. We need to keep track of the number of bytes
- // we discarded, though, so that we can call input_->BackUp() to back
- // up over them on destruction.
- // The following line is equivalent to:
- // overflow_bytes_ = total_bytes_read_ + buffer_size - INT_MAX;
- // except that it avoids overflows. Signed integer overflow has
- // undefined results according to the C standard.
- overflow_bytes_ = total_bytes_read_ - (INT_MAX - buffer_size);
- buffer_end_ -= overflow_bytes_;
- total_bytes_read_ = INT_MAX;
- }
- RecomputeBufferLimits();
- return true;
- } else {
- buffer_ = NULL;
- buffer_end_ = NULL;
- return false;
- }
- }
- // CodedOutputStream =================================================
- CodedOutputStream::CodedOutputStream(ZeroCopyOutputStream* output)
- : output_(output),
- buffer_(NULL),
- buffer_size_(0),
- total_bytes_(0),
- had_error_(false) {
- // Eagerly Refresh() so buffer space is immediately available.
- Refresh();
- // The Refresh() may have failed. If the client doesn't write any data,
- // though, don't consider this an error. If the client does write data, then
- // another Refresh() will be attempted and it will set the error once again.
- had_error_ = false;
- }
- CodedOutputStream::~CodedOutputStream() {
- if (buffer_size_ > 0) {
- output_->BackUp(buffer_size_);
- }
- }
- bool CodedOutputStream::Skip(int count) {
- if (count < 0) return false;
- while (count > buffer_size_) {
- count -= buffer_size_;
- if (!Refresh()) return false;
- }
- Advance(count);
- return true;
- }
- bool CodedOutputStream::GetDirectBufferPointer(void** data, int* size) {
- if (buffer_size_ == 0 && !Refresh()) return false;
- *data = buffer_;
- *size = buffer_size_;
- return true;
- }
- void CodedOutputStream::WriteRaw(const void* data, int size) {
- while (buffer_size_ < size) {
- memcpy(buffer_, data, buffer_size_);
- size -= buffer_size_;
- data = reinterpret_cast<const uint8*>(data) + buffer_size_;
- if (!Refresh()) return;
- }
- memcpy(buffer_, data, size);
- Advance(size);
- }
- uint8* CodedOutputStream::WriteRawToArray(
- const void* data, int size, uint8* target) {
- memcpy(target, data, size);
- return target + size;
- }
- void CodedOutputStream::WriteLittleEndian32(uint32 value) {
- uint8 bytes[sizeof(value)];
- bool use_fast = buffer_size_ >= sizeof(value);
- uint8* ptr = use_fast ? buffer_ : bytes;
- WriteLittleEndian32ToArray(value, ptr);
- if (use_fast) {
- Advance(sizeof(value));
- } else {
- WriteRaw(bytes, sizeof(value));
- }
- }
- void CodedOutputStream::WriteLittleEndian64(uint64 value) {
- uint8 bytes[sizeof(value)];
- bool use_fast = buffer_size_ >= sizeof(value);
- uint8* ptr = use_fast ? buffer_ : bytes;
- WriteLittleEndian64ToArray(value, ptr);
- if (use_fast) {
- Advance(sizeof(value));
- } else {
- WriteRaw(bytes, sizeof(value));
- }
- }
- inline uint8* CodedOutputStream::WriteVarint32FallbackToArrayInline(
- uint32 value, uint8* target) {
- target[0] = static_cast<uint8>(value | 0x80);
- if (value >= (1 << 7)) {
- target[1] = static_cast<uint8>((value >> 7) | 0x80);
- if (value >= (1 << 14)) {
- target[2] = static_cast<uint8>((value >> 14) | 0x80);
- if (value >= (1 << 21)) {
- target[3] = static_cast<uint8>((value >> 21) | 0x80);
- if (value >= (1 << 28)) {
- target[4] = static_cast<uint8>(value >> 28);
- return target + 5;
- } else {
- target[3] &= 0x7F;
- return target + 4;
- }
- } else {
- target[2] &= 0x7F;
- return target + 3;
- }
- } else {
- target[1] &= 0x7F;
- return target + 2;
- }
- } else {
- target[0] &= 0x7F;
- return target + 1;
- }
- }
- void CodedOutputStream::WriteVarint32(uint32 value) {
- if (buffer_size_ >= kMaxVarint32Bytes) {
- // Fast path: We have enough bytes left in the buffer to guarantee that
- // this write won't cross the end, so we can skip the checks.
- uint8* target = buffer_;
- uint8* end = WriteVarint32FallbackToArrayInline(value, target);
- int size = end - target;
- Advance(size);
- } else {
- // Slow path: This write might cross the end of the buffer, so we
- // compose the bytes first then use WriteRaw().
- uint8 bytes[kMaxVarint32Bytes];
- int size = 0;
- while (value > 0x7F) {
- bytes[size++] = (static_cast<uint8>(value) & 0x7F) | 0x80;
- value >>= 7;
- }
- bytes[size++] = static_cast<uint8>(value) & 0x7F;
- WriteRaw(bytes, size);
- }
- }
- uint8* CodedOutputStream::WriteVarint32FallbackToArray(
- uint32 value, uint8* target) {
- return WriteVarint32FallbackToArrayInline(value, target);
- }
- inline uint8* CodedOutputStream::WriteVarint64ToArrayInline(
- uint64 value, uint8* target) {
- // Splitting into 32-bit pieces gives better performance on 32-bit
- // processors.
- uint32 part0 = static_cast<uint32>(value );
- uint32 part1 = static_cast<uint32>(value >> 28);
- uint32 part2 = static_cast<uint32>(value >> 56);
- int size;
- // Here we can't really optimize for small numbers, since the value is
- // split into three parts. Cheking for numbers < 128, for instance,
- // would require three comparisons, since you'd have to make sure part1
- // and part2 are zero. However, if the caller is using 64-bit integers,
- // it is likely that they expect the numbers to often be very large, so
- // we probably don't want to optimize for small numbers anyway. Thus,
- // we end up with a hardcoded binary search tree...
- if (part2 == 0) {
- if (part1 == 0) {
- if (part0 < (1 << 14)) {
- if (part0 < (1 << 7)) {
- size = 1; goto size1;
- } else {
- size = 2; goto size2;
- }
- } else {
- if (part0 < (1 << 21)) {
- size = 3; goto size3;
- } else {
- size = 4; goto size4;
- }
- }
- } else {
- if (part1 < (1 << 14)) {
- if (part1 < (1 << 7)) {
- size = 5; goto size5;
- } else {
- size = 6; goto size6;
- }
- } else {
- if (part1 < (1 << 21)) {
- size = 7; goto size7;
- } else {
- size = 8; goto size8;
- }
- }
- }
- } else {
- if (part2 < (1 << 7)) {
- size = 9; goto size9;
- } else {
- size = 10; goto size10;
- }
- }
- GOOGLE_LOG(FATAL) << "Can't get here.";
- size10: target[9] = static_cast<uint8>((part2 >> 7) | 0x80);
- size9 : target[8] = static_cast<uint8>((part2 ) | 0x80);
- size8 : target[7] = static_cast<uint8>((part1 >> 21) | 0x80);
- size7 : target[6] = static_cast<uint8>((part1 >> 14) | 0x80);
- size6 : target[5] = static_cast<uint8>((part1 >> 7) | 0x80);
- size5 : target[4] = static_cast<uint8>((part1 ) | 0x80);
- size4 : target[3] = static_cast<uint8>((part0 >> 21) | 0x80);
- size3 : target[2] = static_cast<uint8>((part0 >> 14) | 0x80);
- size2 : target[1] = static_cast<uint8>((part0 >> 7) | 0x80);
- size1 : target[0] = static_cast<uint8>((part0 ) | 0x80);
- target[size-1] &= 0x7F;
- return target + size;
- }
- void CodedOutputStream::WriteVarint64(uint64 value) {
- if (buffer_size_ >= kMaxVarintBytes) {
- // Fast path: We have enough bytes left in the buffer to guarantee that
- // this write won't cross the end, so we can skip the checks.
- uint8* target = buffer_;
- uint8* end = WriteVarint64ToArrayInline(value, target);
- int size = end - target;
- Advance(size);
- } else {
- // Slow path: This write might cross the end of the buffer, so we
- // compose the bytes first then use WriteRaw().
- uint8 bytes[kMaxVarintBytes];
- int size = 0;
- while (value > 0x7F) {
- bytes[size++] = (static_cast<uint8>(value) & 0x7F) | 0x80;
- value >>= 7;
- }
- bytes[size++] = static_cast<uint8>(value) & 0x7F;
- WriteRaw(bytes, size);
- }
- }
- uint8* CodedOutputStream::WriteVarint64ToArray(
- uint64 value, uint8* target) {
- return WriteVarint64ToArrayInline(value, target);
- }
- bool CodedOutputStream::Refresh() {
- void* void_buffer;
- if (output_->Next(&void_buffer, &buffer_size_)) {
- buffer_ = reinterpret_cast<uint8*>(void_buffer);
- total_bytes_ += buffer_size_;
- return true;
- } else {
- buffer_ = NULL;
- buffer_size_ = 0;
- had_error_ = true;
- return false;
- }
- }
- int CodedOutputStream::VarintSize32Fallback(uint32 value) {
- if (value < (1 << 7)) {
- return 1;
- } else if (value < (1 << 14)) {
- return 2;
- } else if (value < (1 << 21)) {
- return 3;
- } else if (value < (1 << 28)) {
- return 4;
- } else {
- return 5;
- }
- }
- int CodedOutputStream::VarintSize64(uint64 value) {
- if (value < (1ull << 35)) {
- if (value < (1ull << 7)) {
- return 1;
- } else if (value < (1ull << 14)) {
- return 2;
- } else if (value < (1ull << 21)) {
- return 3;
- } else if (value < (1ull << 28)) {
- return 4;
- } else {
- return 5;
- }
- } else {
- if (value < (1ull << 42)) {
- return 6;
- } else if (value < (1ull << 49)) {
- return 7;
- } else if (value < (1ull << 56)) {
- return 8;
- } else if (value < (1ull << 63)) {
- return 9;
- } else {
- return 10;
- }
- }
- }
- } // namespace io
- } // namespace protobuf
- } // namespace google