diff options
Diffstat (limited to 'third_party/protobuf/3.6.0/src/google/protobuf/io/coded_stream.h')
| -rw-r--r-- | third_party/protobuf/3.6.0/src/google/protobuf/io/coded_stream.h | 1400 |
1 files changed, 1400 insertions, 0 deletions
diff --git a/third_party/protobuf/3.6.0/src/google/protobuf/io/coded_stream.h b/third_party/protobuf/3.6.0/src/google/protobuf/io/coded_stream.h new file mode 100644 index 0000000000..0f70ecde4c --- /dev/null +++ b/third_party/protobuf/3.6.0/src/google/protobuf/io/coded_stream.h @@ -0,0 +1,1400 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// 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 file contains the CodedInputStream and CodedOutputStream classes, +// which wrap a ZeroCopyInputStream or ZeroCopyOutputStream, respectively, +// and allow you to read or write individual pieces of data in various +// formats. In particular, these implement the varint encoding for +// integers, a simple variable-length encoding in which smaller numbers +// take fewer bytes. +// +// Typically these classes will only be used internally by the protocol +// buffer library in order to encode and decode protocol buffers. Clients +// of the library only need to know about this class if they wish to write +// custom message parsing or serialization procedures. +// +// CodedOutputStream example: +// // Write some data to "myfile". First we write a 4-byte "magic number" +// // to identify the file type, then write a length-delimited string. The +// // string is composed of a varint giving the length followed by the raw +// // bytes. +// int fd = open("myfile", O_CREAT | O_WRONLY); +// ZeroCopyOutputStream* raw_output = new FileOutputStream(fd); +// CodedOutputStream* coded_output = new CodedOutputStream(raw_output); +// +// int magic_number = 1234; +// char text[] = "Hello world!"; +// coded_output->WriteLittleEndian32(magic_number); +// coded_output->WriteVarint32(strlen(text)); +// coded_output->WriteRaw(text, strlen(text)); +// +// delete coded_output; +// delete raw_output; +// close(fd); +// +// CodedInputStream example: +// // Read a file created by the above code. +// int fd = open("myfile", O_RDONLY); +// ZeroCopyInputStream* raw_input = new FileInputStream(fd); +// CodedInputStream coded_input = new CodedInputStream(raw_input); +// +// coded_input->ReadLittleEndian32(&magic_number); +// if (magic_number != 1234) { +// cerr << "File not in expected format." << endl; +// return; +// } +// +// uint32 size; +// coded_input->ReadVarint32(&size); +// +// char* text = new char[size + 1]; +// coded_input->ReadRaw(buffer, size); +// text[size] = '\0'; +// +// delete coded_input; +// delete raw_input; +// close(fd); +// +// cout << "Text is: " << text << endl; +// delete [] text; +// +// For those who are interested, varint encoding is defined as follows: +// +// The encoding operates on unsigned integers of up to 64 bits in length. +// Each byte of the encoded value has the format: +// * bits 0-6: Seven bits of the number being encoded. +// * bit 7: Zero if this is the last byte in the encoding (in which +// case all remaining bits of the number are zero) or 1 if +// more bytes follow. +// The first byte contains the least-significant 7 bits of the number, the +// second byte (if present) contains the next-least-significant 7 bits, +// and so on. So, the binary number 1011000101011 would be encoded in two +// bytes as "10101011 00101100". +// +// In theory, varint could be used to encode integers of any length. +// However, for practicality we set a limit at 64 bits. The maximum encoded +// length of a number is thus 10 bytes. + +#ifndef GOOGLE_PROTOBUF_IO_CODED_STREAM_H__ +#define GOOGLE_PROTOBUF_IO_CODED_STREAM_H__ + +#include <assert.h> +#include <atomic> +#include <climits> +#include <string> +#include <utility> +#ifdef _MSC_VER + // Assuming windows is always little-endian. + #if !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST) + #define PROTOBUF_LITTLE_ENDIAN 1 + #endif + #if _MSC_VER >= 1300 && !defined(__INTEL_COMPILER) + // If MSVC has "/RTCc" set, it will complain about truncating casts at + // runtime. This file contains some intentional truncating casts. + #pragma runtime_checks("c", off) + #endif +#else + #include <sys/param.h> // __BYTE_ORDER + #if ((defined(__LITTLE_ENDIAN__) && !defined(__BIG_ENDIAN__)) || \ + (defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN)) && \ + !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST) + #define PROTOBUF_LITTLE_ENDIAN 1 + #endif +#endif +#include <google/protobuf/stubs/common.h> +#include <google/protobuf/stubs/port.h> +#include <google/protobuf/stubs/port.h> + +namespace google { + +namespace protobuf { + +class DescriptorPool; +class MessageFactory; + +namespace internal { void MapTestForceDeterministic(); } + +namespace io { + +// Defined in this file. +class CodedInputStream; +class CodedOutputStream; + +// Defined in other files. +class ZeroCopyInputStream; // zero_copy_stream.h +class ZeroCopyOutputStream; // zero_copy_stream.h + +// Class which reads and decodes binary data which is composed of varint- +// encoded integers and fixed-width pieces. Wraps a ZeroCopyInputStream. +// Most users will not need to deal with CodedInputStream. +// +// Most methods of CodedInputStream that return a bool return false if an +// underlying I/O error occurs or if the data is malformed. Once such a +// failure occurs, the CodedInputStream is broken and is no longer useful. +class LIBPROTOBUF_EXPORT CodedInputStream { + public: + // Create a CodedInputStream that reads from the given ZeroCopyInputStream. + explicit CodedInputStream(ZeroCopyInputStream* input); + + // Create a CodedInputStream that reads from the given flat array. This is + // faster than using an ArrayInputStream. PushLimit(size) is implied by + // this constructor. + explicit CodedInputStream(const uint8* buffer, int size); + + // Destroy the CodedInputStream and position the underlying + // ZeroCopyInputStream at the first unread byte. If an error occurred while + // reading (causing a method to return false), then the exact position of + // the input stream may be anywhere between the last value that was read + // successfully and the stream's byte limit. + ~CodedInputStream(); + + // Return true if this CodedInputStream reads from a flat array instead of + // a ZeroCopyInputStream. + inline bool IsFlat() const; + + // Skips a number of bytes. Returns false if an underlying read error + // occurs. + inline bool Skip(int count); + + // Sets *data to point directly at the unread part of the CodedInputStream's + // underlying buffer, and *size to the size of that buffer, but does not + // advance the stream's current position. This will always either produce + // a non-empty buffer or return false. If the caller consumes any of + // this data, it should then call Skip() to skip over the consumed bytes. + // This may be useful for implementing external fast parsing routines for + // types of data not covered by the CodedInputStream interface. + bool GetDirectBufferPointer(const void** data, int* size); + + // Like GetDirectBufferPointer, but this method is inlined, and does not + // attempt to Refresh() if the buffer is currently empty. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + void GetDirectBufferPointerInline(const void** data, int* size); + + // Read raw bytes, copying them into the given buffer. + bool ReadRaw(void* buffer, int size); + + // Like the above, with inlined optimizations. This should only be used + // by the protobuf implementation. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + bool InternalReadRawInline(void* buffer, int size); + + // Like ReadRaw, but reads into a string. + bool ReadString(string* buffer, int size); + // Like the above, with inlined optimizations. This should only be used + // by the protobuf implementation. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + bool InternalReadStringInline(string* buffer, int size); + + + // Read a 32-bit little-endian integer. + bool ReadLittleEndian32(uint32* value); + // Read a 64-bit little-endian integer. + bool ReadLittleEndian64(uint64* value); + + // These methods read from an externally provided buffer. The caller is + // responsible for ensuring that the buffer has sufficient space. + // Read a 32-bit little-endian integer. + static const uint8* ReadLittleEndian32FromArray(const uint8* buffer, + uint32* value); + // Read a 64-bit little-endian integer. + static const uint8* ReadLittleEndian64FromArray(const uint8* buffer, + uint64* value); + + // Read an unsigned integer with Varint encoding, truncating to 32 bits. + // Reading a 32-bit value is equivalent to reading a 64-bit one and casting + // it to uint32, but may be more efficient. + bool ReadVarint32(uint32* value); + // Read an unsigned integer with Varint encoding. + bool ReadVarint64(uint64* value); + + // Reads a varint off the wire into an "int". This should be used for reading + // sizes off the wire (sizes of strings, submessages, bytes fields, etc). + // + // The value from the wire is interpreted as unsigned. If its value exceeds + // the representable value of an integer on this platform, instead of + // truncating we return false. Truncating (as performed by ReadVarint32() + // above) is an acceptable approach for fields representing an integer, but + // when we are parsing a size from the wire, truncating the value would result + // in us misparsing the payload. + bool ReadVarintSizeAsInt(int* value); + + // Read a tag. This calls ReadVarint32() and returns the result, or returns + // zero (which is not a valid tag) if ReadVarint32() fails. Also, ReadTag + // (but not ReadTagNoLastTag) updates the last tag value, which can be checked + // with LastTagWas(). + // + // Always inline because this is only called in one place per parse loop + // but it is called for every iteration of said loop, so it should be fast. + // GCC doesn't want to inline this by default. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE uint32 ReadTag() { + return last_tag_ = ReadTagNoLastTag(); + } + + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE uint32 ReadTagNoLastTag(); + + + // This usually a faster alternative to ReadTag() when cutoff is a manifest + // constant. It does particularly well for cutoff >= 127. The first part + // of the return value is the tag that was read, though it can also be 0 in + // the cases where ReadTag() would return 0. If the second part is true + // then the tag is known to be in [0, cutoff]. If not, the tag either is + // above cutoff or is 0. (There's intentional wiggle room when tag is 0, + // because that can arise in several ways, and for best performance we want + // to avoid an extra "is tag == 0?" check here.) + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + std::pair<uint32, bool> ReadTagWithCutoff(uint32 cutoff) { + std::pair<uint32, bool> result = ReadTagWithCutoffNoLastTag(cutoff); + last_tag_ = result.first; + return result; + } + + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + std::pair<uint32, bool> ReadTagWithCutoffNoLastTag(uint32 cutoff); + + // Usually returns true if calling ReadVarint32() now would produce the given + // value. Will always return false if ReadVarint32() would not return the + // given value. If ExpectTag() returns true, it also advances past + // the varint. For best performance, use a compile-time constant as the + // parameter. + // Always inline because this collapses to a small number of instructions + // when given a constant parameter, but GCC doesn't want to inline by default. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE bool ExpectTag(uint32 expected); + + // Like above, except this reads from the specified buffer. The caller is + // responsible for ensuring that the buffer is large enough to read a varint + // of the expected size. For best performance, use a compile-time constant as + // the expected tag parameter. + // + // Returns a pointer beyond the expected tag if it was found, or NULL if it + // was not. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + static const uint8* ExpectTagFromArray(const uint8* buffer, uint32 expected); + + // Usually returns true if no more bytes can be read. Always returns false + // if more bytes can be read. If ExpectAtEnd() returns true, a subsequent + // call to LastTagWas() will act as if ReadTag() had been called and returned + // zero, and ConsumedEntireMessage() will return true. + bool ExpectAtEnd(); + + // If the last call to ReadTag() or ReadTagWithCutoff() returned the given + // value, returns true. Otherwise, returns false. + // ReadTagNoLastTag/ReadTagWithCutoffNoLastTag do not preserve the last + // returned value. + // + // This is needed because parsers for some types of embedded messages + // (with field type TYPE_GROUP) don't actually know that they've reached the + // end of a message until they see an ENDGROUP tag, which was actually part + // of the enclosing message. The enclosing message would like to check that + // tag to make sure it had the right number, so it calls LastTagWas() on + // return from the embedded parser to check. + bool LastTagWas(uint32 expected); + void SetLastTag(uint32 tag) { last_tag_ = tag; } + + // When parsing message (but NOT a group), this method must be called + // immediately after MergeFromCodedStream() returns (if it returns true) + // to further verify that the message ended in a legitimate way. For + // example, this verifies that parsing did not end on an end-group tag. + // It also checks for some cases where, due to optimizations, + // MergeFromCodedStream() can incorrectly return true. + bool ConsumedEntireMessage(); + + // Limits ---------------------------------------------------------- + // Limits are used when parsing length-delimited embedded messages. + // After the message's length is read, PushLimit() is used to prevent + // the CodedInputStream from reading beyond that length. Once the + // embedded message has been parsed, PopLimit() is called to undo the + // limit. + + // Opaque type used with PushLimit() and PopLimit(). Do not modify + // values of this type yourself. The only reason that this isn't a + // struct with private internals is for efficiency. + typedef int Limit; + + // Places a limit on the number of bytes that the stream may read, + // starting from the current position. Once the stream hits this limit, + // it will act like the end of the input has been reached until PopLimit() + // is called. + // + // As the names imply, the stream conceptually has a stack of limits. The + // shortest limit on the stack is always enforced, even if it is not the + // top limit. + // + // The value returned by PushLimit() is opaque to the caller, and must + // be passed unchanged to the corresponding call to PopLimit(). + Limit PushLimit(int byte_limit); + + // Pops the last limit pushed by PushLimit(). The input must be the value + // returned by that call to PushLimit(). + void PopLimit(Limit limit); + + // Returns the number of bytes left until the nearest limit on the + // stack is hit, or -1 if no limits are in place. + int BytesUntilLimit() const; + + // Returns current position relative to the beginning of the input stream. + int CurrentPosition() const; + + // Total Bytes Limit ----------------------------------------------- + // To prevent malicious users from sending excessively large messages + // and causing memory exhaustion, CodedInputStream imposes a hard limit on + // the total number of bytes it will read. + + // Sets the maximum number of bytes that this CodedInputStream will read + // before refusing to continue. To prevent servers from allocating enormous + // amounts of memory to hold parsed messages, the maximum message length + // should be limited to the shortest length that will not harm usability. + // The default limit is INT_MAX (~2GB) and apps should set shorter limits + // if possible. An error will always be printed to stderr if the limit is + // reached. + // + // Note: setting a limit less than the current read position is interpreted + // as a limit on the current position. + // + // This is unrelated to PushLimit()/PopLimit(). + void SetTotalBytesLimit(int total_bytes_limit); + + PROTOBUF_RUNTIME_DEPRECATED( + "Please use the single parameter version of SetTotalBytesLimit(). The " + "second parameter is ignored.") + void SetTotalBytesLimit(int total_bytes_limit, int) { + SetTotalBytesLimit(total_bytes_limit); + } + + // The Total Bytes Limit minus the Current Position, or -1 if the total bytes + // limit is INT_MAX. + int BytesUntilTotalBytesLimit() const; + + // Recursion Limit ------------------------------------------------- + // To prevent corrupt or malicious messages from causing stack overflows, + // we must keep track of the depth of recursion when parsing embedded + // messages and groups. CodedInputStream keeps track of this because it + // is the only object that is passed down the stack during parsing. + + // Sets the maximum recursion depth. The default is 100. + void SetRecursionLimit(int limit); + + + // Increments the current recursion depth. Returns true if the depth is + // under the limit, false if it has gone over. + bool IncrementRecursionDepth(); + + // Decrements the recursion depth if possible. + void DecrementRecursionDepth(); + + // Decrements the recursion depth blindly. This is faster than + // DecrementRecursionDepth(). It should be used only if all previous + // increments to recursion depth were successful. + void UnsafeDecrementRecursionDepth(); + + // Shorthand for make_pair(PushLimit(byte_limit), --recursion_budget_). + // Using this can reduce code size and complexity in some cases. The caller + // is expected to check that the second part of the result is non-negative (to + // bail out if the depth of recursion is too high) and, if all is well, to + // later pass the first part of the result to PopLimit() or similar. + std::pair<CodedInputStream::Limit, int> IncrementRecursionDepthAndPushLimit( + int byte_limit); + + // Shorthand for PushLimit(ReadVarint32(&length) ? length : 0). + Limit ReadLengthAndPushLimit(); + + // Helper that is equivalent to: { + // bool result = ConsumedEntireMessage(); + // PopLimit(limit); + // UnsafeDecrementRecursionDepth(); + // return result; } + // Using this can reduce code size and complexity in some cases. + // Do not use unless the current recursion depth is greater than zero. + bool DecrementRecursionDepthAndPopLimit(Limit limit); + + // Helper that is equivalent to: { + // bool result = ConsumedEntireMessage(); + // PopLimit(limit); + // return result; } + // Using this can reduce code size and complexity in some cases. + bool CheckEntireMessageConsumedAndPopLimit(Limit limit); + + // Extension Registry ---------------------------------------------- + // ADVANCED USAGE: 99.9% of people can ignore this section. + // + // By default, when parsing extensions, the parser looks for extension + // definitions in the pool which owns the outer message's Descriptor. + // However, you may call SetExtensionRegistry() to provide an alternative + // pool instead. This makes it possible, for example, to parse a message + // using a generated class, but represent some extensions using + // DynamicMessage. + + // Set the pool used to look up extensions. Most users do not need to call + // this as the correct pool will be chosen automatically. + // + // WARNING: It is very easy to misuse this. Carefully read the requirements + // below. Do not use this unless you are sure you need it. Almost no one + // does. + // + // Let's say you are parsing a message into message object m, and you want + // to take advantage of SetExtensionRegistry(). You must follow these + // requirements: + // + // The given DescriptorPool must contain m->GetDescriptor(). It is not + // sufficient for it to simply contain a descriptor that has the same name + // and content -- it must be the *exact object*. In other words: + // assert(pool->FindMessageTypeByName(m->GetDescriptor()->full_name()) == + // m->GetDescriptor()); + // There are two ways to satisfy this requirement: + // 1) Use m->GetDescriptor()->pool() as the pool. This is generally useless + // because this is the pool that would be used anyway if you didn't call + // SetExtensionRegistry() at all. + // 2) Use a DescriptorPool which has m->GetDescriptor()->pool() as an + // "underlay". Read the documentation for DescriptorPool for more + // information about underlays. + // + // You must also provide a MessageFactory. This factory will be used to + // construct Message objects representing extensions. The factory's + // GetPrototype() MUST return non-NULL for any Descriptor which can be found + // through the provided pool. + // + // If the provided factory might return instances of protocol-compiler- + // generated (i.e. compiled-in) types, or if the outer message object m is + // a generated type, then the given factory MUST have this property: If + // GetPrototype() is given a Descriptor which resides in + // DescriptorPool::generated_pool(), the factory MUST return the same + // prototype which MessageFactory::generated_factory() would return. That + // is, given a descriptor for a generated type, the factory must return an + // instance of the generated class (NOT DynamicMessage). However, when + // given a descriptor for a type that is NOT in generated_pool, the factory + // is free to return any implementation. + // + // The reason for this requirement is that generated sub-objects may be + // accessed via the standard (non-reflection) extension accessor methods, + // and these methods will down-cast the object to the generated class type. + // If the object is not actually of that type, the results would be undefined. + // On the other hand, if an extension is not compiled in, then there is no + // way the code could end up accessing it via the standard accessors -- the + // only way to access the extension is via reflection. When using reflection, + // DynamicMessage and generated messages are indistinguishable, so it's fine + // if these objects are represented using DynamicMessage. + // + // Using DynamicMessageFactory on which you have called + // SetDelegateToGeneratedFactory(true) should be sufficient to satisfy the + // above requirement. + // + // If either pool or factory is NULL, both must be NULL. + // + // Note that this feature is ignored when parsing "lite" messages as they do + // not have descriptors. + void SetExtensionRegistry(const DescriptorPool* pool, + MessageFactory* factory); + + // Get the DescriptorPool set via SetExtensionRegistry(), or NULL if no pool + // has been provided. + const DescriptorPool* GetExtensionPool(); + + // Get the MessageFactory set via SetExtensionRegistry(), or NULL if no + // factory has been provided. + MessageFactory* GetExtensionFactory(); + + private: + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CodedInputStream); + + const uint8* buffer_; + const uint8* buffer_end_; // pointer to the end of the buffer. + ZeroCopyInputStream* input_; + int total_bytes_read_; // total bytes read from input_, including + // the current buffer + + // If total_bytes_read_ surpasses INT_MAX, we record the extra bytes here + // so that we can BackUp() on destruction. + int overflow_bytes_; + + // LastTagWas() stuff. + uint32 last_tag_; // result of last ReadTag() or ReadTagWithCutoff(). + + // This is set true by ReadTag{Fallback/Slow}() if it is called when exactly + // at EOF, or by ExpectAtEnd() when it returns true. This happens when we + // reach the end of a message and attempt to read another tag. + bool legitimate_message_end_; + + // See EnableAliasing(). + bool aliasing_enabled_; + + // Limits + Limit current_limit_; // if position = -1, no limit is applied + + // For simplicity, if the current buffer crosses a limit (either a normal + // limit created by PushLimit() or the total bytes limit), buffer_size_ + // only tracks the number of bytes before that limit. This field + // contains the number of bytes after it. Note that this implies that if + // buffer_size_ == 0 and buffer_size_after_limit_ > 0, we know we've + // hit a limit. However, if both are zero, it doesn't necessarily mean + // we aren't at a limit -- the buffer may have ended exactly at the limit. + int buffer_size_after_limit_; + + // Maximum number of bytes to read, period. This is unrelated to + // current_limit_. Set using SetTotalBytesLimit(). + int total_bytes_limit_; + + // Current recursion budget, controlled by IncrementRecursionDepth() and + // similar. Starts at recursion_limit_ and goes down: if this reaches + // -1 we are over budget. + int recursion_budget_; + // Recursion depth limit, set by SetRecursionLimit(). + int recursion_limit_; + + // See SetExtensionRegistry(). + const DescriptorPool* extension_pool_; + MessageFactory* extension_factory_; + + // Private member functions. + + // Fallback when Skip() goes past the end of the current buffer. + bool SkipFallback(int count, int original_buffer_size); + + // Advance the buffer by a given number of bytes. + void Advance(int amount); + + // Back up input_ to the current buffer position. + void BackUpInputToCurrentPosition(); + + // Recomputes the value of buffer_size_after_limit_. Must be called after + // current_limit_ or total_bytes_limit_ changes. + void RecomputeBufferLimits(); + + // Writes an error message saying that we hit total_bytes_limit_. + void PrintTotalBytesLimitError(); + + // Called when the buffer runs out to request more data. Implies an + // Advance(BufferSize()). + bool Refresh(); + + // When parsing varints, we optimize for the common case of small values, and + // then optimize for the case when the varint fits within the current buffer + // piece. The Fallback method is used when we can't use the one-byte + // optimization. The Slow method is yet another fallback when the buffer is + // not large enough. Making the slow path out-of-line speeds up the common + // case by 10-15%. The slow path is fairly uncommon: it only triggers when a + // message crosses multiple buffers. Note: ReadVarint32Fallback() and + // ReadVarint64Fallback() are called frequently and generally not inlined, so + // they have been optimized to avoid "out" parameters. The former returns -1 + // if it fails and the uint32 it read otherwise. The latter has a bool + // indicating success or failure as part of its return type. + int64 ReadVarint32Fallback(uint32 first_byte_or_zero); + int ReadVarintSizeAsIntFallback(); + std::pair<uint64, bool> ReadVarint64Fallback(); + bool ReadVarint32Slow(uint32* value); + bool ReadVarint64Slow(uint64* value); + int ReadVarintSizeAsIntSlow(); + bool ReadLittleEndian32Fallback(uint32* value); + bool ReadLittleEndian64Fallback(uint64* value); + + // Fallback/slow methods for reading tags. These do not update last_tag_, + // but will set legitimate_message_end_ if we are at the end of the input + // stream. + uint32 ReadTagFallback(uint32 first_byte_or_zero); + uint32 ReadTagSlow(); + bool ReadStringFallback(string* buffer, int size); + + // Return the size of the buffer. + int BufferSize() const; + + static const int kDefaultTotalBytesLimit = INT_MAX; + + static int default_recursion_limit_; // 100 by default. +}; + +// Class which encodes and writes binary data which is composed of varint- +// encoded integers and fixed-width pieces. Wraps a ZeroCopyOutputStream. +// Most users will not need to deal with CodedOutputStream. +// +// Most methods of CodedOutputStream which return a bool return false if an +// underlying I/O error occurs. Once such a failure occurs, the +// CodedOutputStream is broken and is no longer useful. The Write* methods do +// not return the stream status, but will invalidate the stream if an error +// occurs. The client can probe HadError() to determine the status. +// +// Note that every method of CodedOutputStream which writes some data has +// a corresponding static "ToArray" version. These versions write directly +// to the provided buffer, returning a pointer past the last written byte. +// They require that the buffer has sufficient capacity for the encoded data. +// This allows an optimization where we check if an output stream has enough +// space for an entire message before we start writing and, if there is, we +// call only the ToArray methods to avoid doing bound checks for each +// individual value. +// i.e., in the example above: +// +// CodedOutputStream coded_output = new CodedOutputStream(raw_output); +// int magic_number = 1234; +// char text[] = "Hello world!"; +// +// int coded_size = sizeof(magic_number) + +// CodedOutputStream::VarintSize32(strlen(text)) + +// strlen(text); +// +// uint8* buffer = +// coded_output->GetDirectBufferForNBytesAndAdvance(coded_size); +// if (buffer != NULL) { +// // The output stream has enough space in the buffer: write directly to +// // the array. +// buffer = CodedOutputStream::WriteLittleEndian32ToArray(magic_number, +// buffer); +// buffer = CodedOutputStream::WriteVarint32ToArray(strlen(text), buffer); +// buffer = CodedOutputStream::WriteRawToArray(text, strlen(text), buffer); +// } else { +// // Make bound-checked writes, which will ask the underlying stream for +// // more space as needed. +// coded_output->WriteLittleEndian32(magic_number); +// coded_output->WriteVarint32(strlen(text)); +// coded_output->WriteRaw(text, strlen(text)); +// } +// +// delete coded_output; +class LIBPROTOBUF_EXPORT CodedOutputStream { + public: + // Create an CodedOutputStream that writes to the given ZeroCopyOutputStream. + explicit CodedOutputStream(ZeroCopyOutputStream* output); + CodedOutputStream(ZeroCopyOutputStream* output, bool do_eager_refresh); + + // Destroy the CodedOutputStream and position the underlying + // ZeroCopyOutputStream immediately after the last byte written. + ~CodedOutputStream(); + + // Trims any unused space in the underlying buffer so that its size matches + // the number of bytes written by this stream. The underlying buffer will + // automatically be trimmed when this stream is destroyed; this call is only + // necessary if the underlying buffer is accessed *before* the stream is + // destroyed. + void Trim(); + + // Skips a number of bytes, leaving the bytes unmodified in the underlying + // buffer. Returns false if an underlying write error occurs. This is + // mainly useful with GetDirectBufferPointer(). + bool Skip(int count); + + // Sets *data to point directly at the unwritten part of the + // CodedOutputStream's underlying buffer, and *size to the size of that + // buffer, but does not advance the stream's current position. This will + // always either produce a non-empty buffer or return false. If the caller + // writes any data to this buffer, it should then call Skip() to skip over + // the consumed bytes. This may be useful for implementing external fast + // serialization routines for types of data not covered by the + // CodedOutputStream interface. + bool GetDirectBufferPointer(void** data, int* size); + + // If there are at least "size" bytes available in the current buffer, + // returns a pointer directly into the buffer and advances over these bytes. + // The caller may then write directly into this buffer (e.g. using the + // *ToArray static methods) rather than go through CodedOutputStream. If + // there are not enough bytes available, returns NULL. The return pointer is + // invalidated as soon as any other non-const method of CodedOutputStream + // is called. + inline uint8* GetDirectBufferForNBytesAndAdvance(int size); + + // Write raw bytes, copying them from the given buffer. + void WriteRaw(const void* buffer, int size); + // Like WriteRaw() but will try to write aliased data if aliasing is + // turned on. + void WriteRawMaybeAliased(const void* data, int size); + // Like WriteRaw() but writing directly to the target array. + // This is _not_ inlined, as the compiler often optimizes memcpy into inline + // copy loops. Since this gets called by every field with string or bytes + // type, inlining may lead to a significant amount of code bloat, with only a + // minor performance gain. + static uint8* WriteRawToArray(const void* buffer, int size, uint8* target); + + // Equivalent to WriteRaw(str.data(), str.size()). + void WriteString(const string& str); + // Like WriteString() but writing directly to the target array. + static uint8* WriteStringToArray(const string& str, uint8* target); + // Write the varint-encoded size of str followed by str. + static uint8* WriteStringWithSizeToArray(const string& str, uint8* target); + + + // Instructs the CodedOutputStream to allow the underlying + // ZeroCopyOutputStream to hold pointers to the original structure instead of + // copying, if it supports it (i.e. output->AllowsAliasing() is true). If the + // underlying stream does not support aliasing, then enabling it has no + // affect. For now, this only affects the behavior of + // WriteRawMaybeAliased(). + // + // NOTE: It is caller's responsibility to ensure that the chunk of memory + // remains live until all of the data has been consumed from the stream. + void EnableAliasing(bool enabled); + + // Write a 32-bit little-endian integer. + void WriteLittleEndian32(uint32 value); + // Like WriteLittleEndian32() but writing directly to the target array. + static uint8* WriteLittleEndian32ToArray(uint32 value, uint8* target); + // Write a 64-bit little-endian integer. + void WriteLittleEndian64(uint64 value); + // Like WriteLittleEndian64() but writing directly to the target array. + static uint8* WriteLittleEndian64ToArray(uint64 value, uint8* target); + + // Write an unsigned integer with Varint encoding. Writing a 32-bit value + // is equivalent to casting it to uint64 and writing it as a 64-bit value, + // but may be more efficient. + void WriteVarint32(uint32 value); + // Like WriteVarint32() but writing directly to the target array. + static uint8* WriteVarint32ToArray(uint32 value, uint8* target); + // Write an unsigned integer with Varint encoding. + void WriteVarint64(uint64 value); + // Like WriteVarint64() but writing directly to the target array. + static uint8* WriteVarint64ToArray(uint64 value, uint8* target); + + // Equivalent to WriteVarint32() except when the value is negative, + // in which case it must be sign-extended to a full 10 bytes. + void WriteVarint32SignExtended(int32 value); + // Like WriteVarint32SignExtended() but writing directly to the target array. + static uint8* WriteVarint32SignExtendedToArray(int32 value, uint8* target); + + // This is identical to WriteVarint32(), but optimized for writing tags. + // In particular, if the input is a compile-time constant, this method + // compiles down to a couple instructions. + // Always inline because otherwise the aformentioned optimization can't work, + // but GCC by default doesn't want to inline this. + void WriteTag(uint32 value); + // Like WriteTag() but writing directly to the target array. + GOOGLE_PROTOBUF_ATTRIBUTE_ALWAYS_INLINE + static uint8* WriteTagToArray(uint32 value, uint8* target); + + // Returns the number of bytes needed to encode the given value as a varint. + static size_t VarintSize32(uint32 value); + // Returns the number of bytes needed to encode the given value as a varint. + static size_t VarintSize64(uint64 value); + + // If negative, 10 bytes. Otheriwse, same as VarintSize32(). + static size_t VarintSize32SignExtended(int32 value); + + // Compile-time equivalent of VarintSize32(). + template <uint32 Value> + struct StaticVarintSize32 { + static const size_t value = + (Value < (1 << 7)) + ? 1 + : (Value < (1 << 14)) + ? 2 + : (Value < (1 << 21)) + ? 3 + : (Value < (1 << 28)) + ? 4 + : 5; + }; + + // Returns the total number of bytes written since this object was created. + inline int ByteCount() const; + + // Returns true if there was an underlying I/O error since this object was + // created. + bool HadError() const { return had_error_; } + + // Deterministic serialization, if requested, guarantees that for a given + // binary, equal messages will always be serialized to the same bytes. This + // implies: + // . repeated serialization of a message will return the same bytes + // . different processes of the same binary (which may be executing on + // different machines) will serialize equal messages to the same bytes. + // + // Note the deterministic serialization is NOT canonical across languages; it + // is also unstable across different builds with schema changes due to unknown + // fields. Users who need canonical serialization, e.g., persistent storage in + // a canonical form, fingerprinting, etc., should define their own + // canonicalization specification and implement the serializer using + // reflection APIs rather than relying on this API. + // + // If deterministic serialization is requested, the serializer will + // sort map entries by keys in lexicographical order or numerical order. + // (This is an implementation detail and may subject to change.) + // + // There are two ways to determine whether serialization should be + // deterministic for this CodedOutputStream. If SetSerializationDeterministic + // has not yet been called, then the default comes from the global default, + // which is false, until SetDefaultSerializationDeterministic has been called. + // Otherwise, SetSerializationDeterministic has been called, and the last + // value passed to it is all that matters. + void SetSerializationDeterministic(bool value) { + is_serialization_deterministic_ = value; + } + // See above. Also, note that users of this CodedOutputStream may need to + // call IsSerializationDeterministic() to serialize in the intended way. This + // CodedOutputStream cannot enforce a desire for deterministic serialization + // by itself. + bool IsSerializationDeterministic() const { + return is_serialization_deterministic_; + } + + static bool IsDefaultSerializationDeterministic() { + return default_serialization_deterministic_.load(std::memory_order_relaxed) != 0; + } + + private: + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CodedOutputStream); + + ZeroCopyOutputStream* output_; + uint8* buffer_; + int buffer_size_; + int total_bytes_; // Sum of sizes of all buffers seen so far. + bool had_error_; // Whether an error occurred during output. + bool aliasing_enabled_; // See EnableAliasing(). + bool is_serialization_deterministic_; + static std::atomic<bool> default_serialization_deterministic_; + + // Advance the buffer by a given number of bytes. + void Advance(int amount); + + // Called when the buffer runs out to request more data. Implies an + // Advance(buffer_size_). + bool Refresh(); + + // Like WriteRaw() but may avoid copying if the underlying + // ZeroCopyOutputStream supports it. + void WriteAliasedRaw(const void* buffer, int size); + + // If this write might cross the end of the buffer, we compose the bytes first + // then use WriteRaw(). + void WriteVarint32SlowPath(uint32 value); + void WriteVarint64SlowPath(uint64 value); + + // See above. Other projects may use "friend" to allow them to call this. + // After SetDefaultSerializationDeterministic() completes, all protocol + // buffer serializations will be deterministic by default. Thread safe. + // However, the meaning of "after" is subtle here: to be safe, each thread + // that wants deterministic serialization by default needs to call + // SetDefaultSerializationDeterministic() or ensure on its own that another + // thread has done so. + friend void ::google::protobuf::internal::MapTestForceDeterministic(); + static void SetDefaultSerializationDeterministic() { + default_serialization_deterministic_.store(true, std::memory_order_relaxed); + } +}; + +// inline methods ==================================================== +// The vast majority of varints are only one byte. These inline +// methods optimize for that case. + +inline bool CodedInputStream::ReadVarint32(uint32* value) { + uint32 v = 0; + if (GOOGLE_PREDICT_TRUE(buffer_ < buffer_end_)) { + v = *buffer_; + if (v < 0x80) { + *value = v; + Advance(1); + return true; + } + } + int64 result = ReadVarint32Fallback(v); + *value = static_cast<uint32>(result); + return result >= 0; +} + +inline bool CodedInputStream::ReadVarint64(uint64* value) { + if (GOOGLE_PREDICT_TRUE(buffer_ < buffer_end_) && *buffer_ < 0x80) { + *value = *buffer_; + Advance(1); + return true; + } + std::pair<uint64, bool> p = ReadVarint64Fallback(); + *value = p.first; + return p.second; +} + +inline bool CodedInputStream::ReadVarintSizeAsInt(int* value) { + if (GOOGLE_PREDICT_TRUE(buffer_ < buffer_end_)) { + int v = *buffer_; + if (v < 0x80) { + *value = v; + Advance(1); + return true; + } + } + *value = ReadVarintSizeAsIntFallback(); + return *value >= 0; +} + +// static +inline const uint8* CodedInputStream::ReadLittleEndian32FromArray( + const uint8* buffer, + uint32* value) { +#if defined(PROTOBUF_LITTLE_ENDIAN) + memcpy(value, buffer, sizeof(*value)); + return buffer + sizeof(*value); +#else + *value = (static_cast<uint32>(buffer[0]) ) | + (static_cast<uint32>(buffer[1]) << 8) | + (static_cast<uint32>(buffer[2]) << 16) | + (static_cast<uint32>(buffer[3]) << 24); + return buffer + sizeof(*value); +#endif +} +// static +inline const uint8* CodedInputStream::ReadLittleEndian64FromArray( + const uint8* buffer, + uint64* value) { +#if defined(PROTOBUF_LITTLE_ENDIAN) + memcpy(value, buffer, sizeof(*value)); + return buffer + sizeof(*value); +#else + uint32 part0 = (static_cast<uint32>(buffer[0]) ) | + (static_cast<uint32>(buffer[1]) << 8) | + (static_cast<uint32>(buffer[2]) << 16) | + (static_cast<uint32>(buffer[3]) << 24); + uint32 part1 = (static_cast<uint32>(buffer[4]) ) | + (static_cast<uint32>(buffer[5]) << 8) | + (static_cast<uint32>(buffer[6]) << 16) | + (static_cast<uint32>(buffer[7]) << 24); + *value = static_cast<uint64>(part0) | + (static_cast<uint64>(part1) << 32); + return buffer + sizeof(*value); +#endif +} + +inline bool CodedInputStream::ReadLittleEndian32(uint32* value) { +#if defined(PROTOBUF_LITTLE_ENDIAN) + if (GOOGLE_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) { + buffer_ = ReadLittleEndian32FromArray(buffer_, value); + return true; + } else { + return ReadLittleEndian32Fallback(value); + } +#else + return ReadLittleEndian32Fallback(value); +#endif +} + +inline bool CodedInputStream::ReadLittleEndian64(uint64* value) { +#if defined(PROTOBUF_LITTLE_ENDIAN) + if (GOOGLE_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) { + buffer_ = ReadLittleEndian64FromArray(buffer_, value); + return true; + } else { + return ReadLittleEndian64Fallback(value); + } +#else + return ReadLittleEndian64Fallback(value); +#endif +} + +inline uint32 CodedInputStream::ReadTagNoLastTag() { + uint32 v = 0; + if (GOOGLE_PREDICT_TRUE(buffer_ < buffer_end_)) { + v = *buffer_; + if (v < 0x80) { + Advance(1); + return v; + } + } + v = ReadTagFallback(v); + return v; +} + +inline std::pair<uint32, bool> CodedInputStream::ReadTagWithCutoffNoLastTag( + uint32 cutoff) { + // In performance-sensitive code we can expect cutoff to be a compile-time + // constant, and things like "cutoff >= kMax1ByteVarint" to be evaluated at + // compile time. + uint32 first_byte_or_zero = 0; + if (GOOGLE_PREDICT_TRUE(buffer_ < buffer_end_)) { + // Hot case: buffer_ non_empty, buffer_[0] in [1, 128). + // TODO(gpike): Is it worth rearranging this? E.g., if the number of fields + // is large enough then is it better to check for the two-byte case first? + first_byte_or_zero = buffer_[0]; + if (static_cast<int8>(buffer_[0]) > 0) { + const uint32 kMax1ByteVarint = 0x7f; + uint32 tag = buffer_[0]; + Advance(1); + return std::make_pair(tag, cutoff >= kMax1ByteVarint || tag <= cutoff); + } + // Other hot case: cutoff >= 0x80, buffer_ has at least two bytes available, + // and tag is two bytes. The latter is tested by bitwise-and-not of the + // first byte and the second byte. + if (cutoff >= 0x80 && GOOGLE_PREDICT_TRUE(buffer_ + 1 < buffer_end_) && + GOOGLE_PREDICT_TRUE((buffer_[0] & ~buffer_[1]) >= 0x80)) { + const uint32 kMax2ByteVarint = (0x7f << 7) + 0x7f; + uint32 tag = (1u << 7) * buffer_[1] + (buffer_[0] - 0x80); + Advance(2); + // It might make sense to test for tag == 0 now, but it is so rare that + // that we don't bother. A varint-encoded 0 should be one byte unless + // the encoder lost its mind. The second part of the return value of + // this function is allowed to be either true or false if the tag is 0, + // so we don't have to check for tag == 0. We may need to check whether + // it exceeds cutoff. + bool at_or_below_cutoff = cutoff >= kMax2ByteVarint || tag <= cutoff; + return std::make_pair(tag, at_or_below_cutoff); + } + } + // Slow path + const uint32 tag = ReadTagFallback(first_byte_or_zero); + return std::make_pair(tag, static_cast<uint32>(tag - 1) < cutoff); +} + +inline bool CodedInputStream::LastTagWas(uint32 expected) { + return last_tag_ == expected; +} + +inline bool CodedInputStream::ConsumedEntireMessage() { + return legitimate_message_end_; +} + +inline bool CodedInputStream::ExpectTag(uint32 expected) { + if (expected < (1 << 7)) { + if (GOOGLE_PREDICT_TRUE(buffer_ < buffer_end_) && buffer_[0] == expected) { + Advance(1); + return true; + } else { + return false; + } + } else if (expected < (1 << 14)) { + if (GOOGLE_PREDICT_TRUE(BufferSize() >= 2) && + buffer_[0] == static_cast<uint8>(expected | 0x80) && + buffer_[1] == static_cast<uint8>(expected >> 7)) { + Advance(2); + return true; + } else { + return false; + } + } else { + // Don't bother optimizing for larger values. + return false; + } +} + +inline const uint8* CodedInputStream::ExpectTagFromArray( + const uint8* buffer, uint32 expected) { + if (expected < (1 << 7)) { + if (buffer[0] == expected) { + return buffer + 1; + } + } else if (expected < (1 << 14)) { + if (buffer[0] == static_cast<uint8>(expected | 0x80) && + buffer[1] == static_cast<uint8>(expected >> 7)) { + return buffer + 2; + } + } + return NULL; +} + +inline void CodedInputStream::GetDirectBufferPointerInline(const void** data, + int* size) { + *data = buffer_; + *size = static_cast<int>(buffer_end_ - buffer_); +} + +inline bool CodedInputStream::ExpectAtEnd() { + // If we are at a limit we know no more bytes can be read. Otherwise, it's + // hard to say without calling Refresh(), and we'd rather not do that. + + if (buffer_ == buffer_end_ && + ((buffer_size_after_limit_ != 0) || + (total_bytes_read_ == current_limit_))) { + last_tag_ = 0; // Pretend we called ReadTag()... + legitimate_message_end_ = true; // ... and it hit EOF. + return true; + } else { + return false; + } +} + +inline int CodedInputStream::CurrentPosition() const { + return total_bytes_read_ - (BufferSize() + buffer_size_after_limit_); +} + +inline uint8* CodedOutputStream::GetDirectBufferForNBytesAndAdvance(int size) { + if (buffer_size_ < size) { + return NULL; + } else { + uint8* result = buffer_; + Advance(size); + return result; + } +} + +inline uint8* CodedOutputStream::WriteVarint32ToArray(uint32 value, + uint8* target) { + while (value >= 0x80) { + *target = static_cast<uint8>(value | 0x80); + value >>= 7; + ++target; + } + *target = static_cast<uint8>(value); + return target + 1; +} + +inline uint8* CodedOutputStream::WriteVarint64ToArray(uint64 value, + uint8* target) { + while (value >= 0x80) { + *target = static_cast<uint8>(value | 0x80); + value >>= 7; + ++target; + } + *target = static_cast<uint8>(value); + return target + 1; +} + +inline void CodedOutputStream::WriteVarint32SignExtended(int32 value) { + WriteVarint64(static_cast<uint64>(value)); +} + +inline uint8* CodedOutputStream::WriteVarint32SignExtendedToArray( + int32 value, uint8* target) { + return WriteVarint64ToArray(static_cast<uint64>(value), target); +} + +inline uint8* CodedOutputStream::WriteLittleEndian32ToArray(uint32 value, + uint8* target) { +#if defined(PROTOBUF_LITTLE_ENDIAN) + memcpy(target, &value, sizeof(value)); +#else + target[0] = static_cast<uint8>(value); + target[1] = static_cast<uint8>(value >> 8); + target[2] = static_cast<uint8>(value >> 16); + target[3] = static_cast<uint8>(value >> 24); +#endif + return target + sizeof(value); +} + +inline uint8* CodedOutputStream::WriteLittleEndian64ToArray(uint64 value, + uint8* target) { +#if defined(PROTOBUF_LITTLE_ENDIAN) + memcpy(target, &value, sizeof(value)); +#else + uint32 part0 = static_cast<uint32>(value); + uint32 part1 = static_cast<uint32>(value >> 32); + + target[0] = static_cast<uint8>(part0); + target[1] = static_cast<uint8>(part0 >> 8); + target[2] = static_cast<uint8>(part0 >> 16); + target[3] = static_cast<uint8>(part0 >> 24); + target[4] = static_cast<uint8>(part1); + target[5] = static_cast<uint8>(part1 >> 8); + target[6] = static_cast<uint8>(part1 >> 16); + target[7] = static_cast<uint8>(part1 >> 24); +#endif + return target + sizeof(value); +} + +inline void CodedOutputStream::WriteVarint32(uint32 value) { + if (buffer_size_ >= 5) { + // 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 = WriteVarint32ToArray(value, target); + int size = static_cast<int>(end - target); + Advance(size); + } else { + WriteVarint32SlowPath(value); + } +} + +inline void CodedOutputStream::WriteVarint64(uint64 value) { + if (buffer_size_ >= 10) { + // 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 = WriteVarint64ToArray(value, target); + int size = static_cast<int>(end - target); + Advance(size); + } else { + WriteVarint64SlowPath(value); + } +} + +inline void CodedOutputStream::WriteTag(uint32 value) { + WriteVarint32(value); +} + +inline uint8* CodedOutputStream::WriteTagToArray( + uint32 value, uint8* target) { + return WriteVarint32ToArray(value, target); +} + +inline size_t CodedOutputStream::VarintSize32(uint32 value) { + // This computes value == 0 ? 1 : floor(log2(value)) / 7 + 1 + // Use an explicit multiplication to implement the divide of + // a number in the 1..31 range. + // Explicit OR 0x1 to avoid calling Bits::Log2FloorNonZero(0), which is + // undefined. + uint32 log2value = Bits::Log2FloorNonZero(value | 0x1); + return static_cast<size_t>((log2value * 9 + 73) / 64); +} + +inline size_t CodedOutputStream::VarintSize64(uint64 value) { + // 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 Bits::Log2FloorNonZero(0), which is + // undefined. + uint32 log2value = Bits::Log2FloorNonZero64(value | 0x1); + return static_cast<size_t>((log2value * 9 + 73) / 64); +} + +inline size_t CodedOutputStream::VarintSize32SignExtended(int32 value) { + if (value < 0) { + return 10; // TODO(kenton): Make this a symbolic constant. + } else { + return VarintSize32(static_cast<uint32>(value)); + } +} + +inline void CodedOutputStream::WriteString(const string& str) { + WriteRaw(str.data(), static_cast<int>(str.size())); +} + +inline void CodedOutputStream::WriteRawMaybeAliased( + const void* data, int size) { + if (aliasing_enabled_) { + WriteAliasedRaw(data, size); + } else { + WriteRaw(data, size); + } +} + +inline uint8* CodedOutputStream::WriteStringToArray( + const string& str, uint8* target) { + return WriteRawToArray(str.data(), static_cast<int>(str.size()), target); +} + +inline int CodedOutputStream::ByteCount() const { + return total_bytes_ - buffer_size_; +} + +inline void CodedInputStream::Advance(int amount) { + buffer_ += amount; +} + +inline void CodedOutputStream::Advance(int amount) { + buffer_ += amount; + buffer_size_ -= amount; +} + +inline void CodedInputStream::SetRecursionLimit(int limit) { + recursion_budget_ += limit - recursion_limit_; + recursion_limit_ = limit; +} + +inline bool CodedInputStream::IncrementRecursionDepth() { + --recursion_budget_; + return recursion_budget_ >= 0; +} + +inline void CodedInputStream::DecrementRecursionDepth() { + if (recursion_budget_ < recursion_limit_) ++recursion_budget_; +} + +inline void CodedInputStream::UnsafeDecrementRecursionDepth() { + assert(recursion_budget_ < recursion_limit_); + ++recursion_budget_; +} + +inline void CodedInputStream::SetExtensionRegistry(const DescriptorPool* pool, + MessageFactory* factory) { + extension_pool_ = pool; + extension_factory_ = factory; +} + +inline const DescriptorPool* CodedInputStream::GetExtensionPool() { + return extension_pool_; +} + +inline MessageFactory* CodedInputStream::GetExtensionFactory() { + return extension_factory_; +} + +inline int CodedInputStream::BufferSize() const { + return static_cast<int>(buffer_end_ - buffer_); +} + +inline CodedInputStream::CodedInputStream(ZeroCopyInputStream* input) + : buffer_(NULL), + buffer_end_(NULL), + input_(input), + total_bytes_read_(0), + overflow_bytes_(0), + last_tag_(0), + legitimate_message_end_(false), + aliasing_enabled_(false), + current_limit_(kint32max), + buffer_size_after_limit_(0), + total_bytes_limit_(kDefaultTotalBytesLimit), + recursion_budget_(default_recursion_limit_), + recursion_limit_(default_recursion_limit_), + extension_pool_(NULL), + extension_factory_(NULL) { + // Eagerly Refresh() so buffer space is immediately available. + Refresh(); +} + +inline CodedInputStream::CodedInputStream(const uint8* buffer, int size) + : buffer_(buffer), + buffer_end_(buffer + size), + input_(NULL), + total_bytes_read_(size), + overflow_bytes_(0), + last_tag_(0), + legitimate_message_end_(false), + aliasing_enabled_(false), + current_limit_(size), + buffer_size_after_limit_(0), + total_bytes_limit_(kDefaultTotalBytesLimit), + recursion_budget_(default_recursion_limit_), + recursion_limit_(default_recursion_limit_), + extension_pool_(NULL), + extension_factory_(NULL) { + // Note that setting current_limit_ == size is important to prevent some + // code paths from trying to access input_ and segfaulting. +} + +inline bool CodedInputStream::IsFlat() const { + return input_ == NULL; +} + +inline 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; + } + + return SkipFallback(count, original_buffer_size); +} + +} // namespace io +} // namespace protobuf + + +#if defined(_MSC_VER) && _MSC_VER >= 1300 && !defined(__INTEL_COMPILER) + #pragma runtime_checks("c", restore) +#endif // _MSC_VER && !defined(__INTEL_COMPILER) + +} // namespace google +#endif // GOOGLE_PROTOBUF_IO_CODED_STREAM_H__ |