diff options
Diffstat (limited to 'src/google/protobuf/io/coded_stream.cc')
-rw-r--r-- | src/google/protobuf/io/coded_stream.cc | 146 |
1 files changed, 32 insertions, 114 deletions
diff --git a/src/google/protobuf/io/coded_stream.cc b/src/google/protobuf/io/coded_stream.cc index 08394ca7..93748ee3 100644 --- a/src/google/protobuf/io/coded_stream.cc +++ b/src/google/protobuf/io/coded_stream.cc @@ -47,7 +47,6 @@ #include <google/protobuf/stubs/logging.h> #include <google/protobuf/stubs/common.h> #include <google/protobuf/stubs/stl_util.h> -#include <google/protobuf/stubs/port.h> namespace google { @@ -550,9 +549,15 @@ bool CodedInputStream::ReadVarint64Slow(uint64* value) { uint32 b; do { - if (count == kMaxVarintBytes) return false; + if (count == kMaxVarintBytes) { + *value = 0; + return false; + } while (buffer_ == buffer_end_) { - if (!Refresh()) return false; + if (!Refresh()) { + *value = 0; + return false; + } } b = *buffer_; result |= static_cast<uint64>(b & 0x7F) << (7 * count); @@ -602,13 +607,13 @@ bool CodedInputStream::Refresh() { 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."; + GOOGLE_LOG(INFO) << "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, and print total size at the end. total_bytes_warning_threshold_ = -2; @@ -789,104 +794,12 @@ void CodedOutputStream::WriteVarint32SlowPath(uint32 value) { WriteRaw(bytes, size); } -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); +void CodedOutputStream::WriteVarint64SlowPath(uint64 value) { + uint8 bytes[kMaxVarintBytes]; + uint8* target = &bytes[0]; + uint8* end = WriteVarint64ToArray(value, target); + int size = end - target; + WriteRaw(bytes, size); } bool CodedOutputStream::Refresh() { @@ -904,17 +817,22 @@ bool CodedOutputStream::Refresh() { } size_t CodedOutputStream::VarintSize32Fallback(uint32 value) { + // This computes floor(log2(value)) / 7 + 1 + // Use an explicit multiplication to implement the divide of + // a number in the 1..31 range. GOOGLE_DCHECK_NE(0, value); // This is enforced by our caller. - return 1 + Bits::Log2FloorNonZero(value) / 7; + uint32 log2value = Bits::Log2FloorNonZero(value); + return static_cast<size_t>((log2value * 9 + 73) / 64); } size_t CodedOutputStream::VarintSize64(uint64 value) { - if (value < (1 << 7)) { - return 1; - } - - return 1 + Bits::Log2FloorNonZero64(value) / 7; + // This computes value == 0 ? 1 : floor(log2(value)) / 7 + 1 + // Use an explicit multiplication to implement the divide of + // a number in the 1..63 range. + // Explicit OR 0x1 to avoid calling clz(0), which is undefined. + uint32 log2value = Bits::Log2FloorNonZero64(value | 0x1); + return static_cast<size_t>((log2value * 9 + 73) / 64); } uint8* CodedOutputStream::WriteStringWithSizeToArray(const string& str, |