// Copyright 2006-2009 the V8 project authors. 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. #ifndef V8_LOG_UTILS_H_ #define V8_LOG_UTILS_H_ namespace v8 { namespace internal { #ifdef ENABLE_LOGGING_AND_PROFILING // A memory buffer that increments its size as you write in it. Size // is incremented with 'block_size' steps, never exceeding 'max_size'. // During growth, memory contents are never copied. At the end of the // buffer an amount of memory specified in 'seal_size' is reserved. // When writing position reaches max_size - seal_size, buffer auto-seals // itself with 'seal' and allows no further writes. Data pointed by // 'seal' must be available during entire LogDynamicBuffer lifetime. // // An instance of this class is created dynamically by Log. class LogDynamicBuffer { public: LogDynamicBuffer( int block_size, int max_size, const char* seal, int seal_size); ~LogDynamicBuffer(); // Reads contents of the buffer starting from 'from_pos'. Upon // return, 'dest_buf' is filled with the data. Actual amount of data // filled is returned, it is <= 'buf_size'. int Read(int from_pos, char* dest_buf, int buf_size); // Writes 'data' to the buffer, making it larger if necessary. If // data is too big to fit in the buffer, it doesn't get written at // all. In that case, buffer auto-seals itself and stops to accept // any incoming writes. Returns amount of data written (it is either // 'data_size', or 0, if 'data' is too big). int Write(const char* data, int data_size); private: void AllocateBlock(int index) { blocks_[index] = NewArray(block_size_); } int BlockIndex(int pos) const { return pos / block_size_; } int BlocksCount() const { return BlockIndex(max_size_) + 1; } int PosInBlock(int pos) const { return pos % block_size_; } int Seal(); int WriteInternal(const char* data, int data_size); const int block_size_; const int max_size_; const char* seal_; const int seal_size_; ScopedVector blocks_; int write_pos_; int block_index_; int block_write_pos_; bool is_sealed_; }; // Functions and data for performing output of log messages. class Log : public AllStatic { public: // Opens stdout for logging. static void OpenStdout(); // Opens file for logging. static void OpenFile(const char* name); // Opens memory buffer for logging. static void OpenMemoryBuffer(); // Disables logging, but preserves acquired resources. static void stop() { is_stopped_ = true; } // Frees all resources acquired in Open... functions. static void Close(); // See description in include/v8.h. static int GetLogLines(int from_pos, char* dest_buf, int max_size); // Returns whether logging is enabled. static bool IsEnabled() { return !is_stopped_ && (output_handle_ != NULL || output_buffer_ != NULL); } // Size of buffer used for formatting log messages. static const int kMessageBufferSize = 2048; private: typedef int (*WritePtr)(const char* msg, int length); // Initialization function called from Open... functions. static void Init(); // Write functions assume that mutex_ is acquired by the caller. static WritePtr Write; // Implementation of writing to a log file. static int WriteToFile(const char* msg, int length) { ASSERT(output_handle_ != NULL); int rv = fwrite(msg, 1, length, output_handle_); ASSERT(length == rv); return rv; } // Implementation of writing to a memory buffer. static int WriteToMemory(const char* msg, int length) { ASSERT(output_buffer_ != NULL); return output_buffer_->Write(msg, length); } // Whether logging is stopped (e.g. due to insufficient resources). static bool is_stopped_; // When logging is active, either output_handle_ or output_buffer_ is used // to store a pointer to log destination. If logging was opened via OpenStdout // or OpenFile, then output_handle_ is used. If logging was opened // via OpenMemoryBuffer, then output_buffer_ is used. // mutex_ should be acquired before using output_handle_ or output_buffer_. static FILE* output_handle_; static LogDynamicBuffer* output_buffer_; // Size of dynamic buffer block (and dynamic buffer initial size). static const int kDynamicBufferBlockSize = 65536; // Maximum size of dynamic buffer. static const int kMaxDynamicBufferSize = 50 * 1024 * 1024; // Message to "seal" dynamic buffer with. static const char* kDynamicBufferSeal; // mutex_ is a Mutex used for enforcing exclusive // access to the formatting buffer and the log file or log memory buffer. static Mutex* mutex_; // Buffer used for formatting log messages. This is a singleton buffer and // mutex_ should be acquired before using it. static char* message_buffer_; friend class LogMessageBuilder; friend class LogRecordCompressor; }; // An utility class for performing backward reference compression // of string ends. It operates using a window of previous strings. class LogRecordCompressor { public: // 'window_size' is the size of backward lookup window. explicit LogRecordCompressor(int window_size) : buffer_(window_size + kNoCompressionWindowSize), kMaxBackwardReferenceSize( GetBackwardReferenceSize(window_size, Log::kMessageBufferSize)), curr_(-1), prev_(-1) { } ~LogRecordCompressor(); // Fills vector with a compressed version of the previous record. // Returns false if there is no previous record. bool RetrievePreviousCompressed(Vector* prev_record); // Stores a record if it differs from a previous one (or there's no previous). // Returns true, if the record has been stored. bool Store(const Vector& record); private: // The minimum size of a buffer: a place needed for the current and // the previous record. Since there is no place for precedessors of a previous // record, it can't be compressed at all. static const int kNoCompressionWindowSize = 2; // Formatting strings for back references. static const char* kLineBackwardReferenceFormat; static const char* kBackwardReferenceFormat; static int GetBackwardReferenceSize(int distance, int pos); static void PrintBackwardReference(Vector dest, int distance, int pos); ScopedVector< Vector > buffer_; const int kMaxBackwardReferenceSize; int curr_; int prev_; }; // Utility class for formatting log messages. It fills the message into the // static buffer in Log. class LogMessageBuilder BASE_EMBEDDED { public: // Create a message builder starting from position 0. This acquires the mutex // in the log as well. explicit LogMessageBuilder(); ~LogMessageBuilder() { } // Append string data to the log message. void Append(const char* format, ...); // Append string data to the log message. void AppendVA(const char* format, va_list args); // Append a character to the log message. void Append(const char c); // Append a heap string. void Append(String* str); // Appends an address, compressing it if needed by offsetting // from Logger::last_address_. void AppendAddress(Address addr); // Appends an address, compressing it if needed. void AppendAddress(Address addr, Address bias); void AppendDetailed(String* str, bool show_impl_info); // Append a portion of a string. void AppendStringPart(const char* str, int len); // Stores log message into compressor, returns true if the message // was stored (i.e. doesn't repeat the previous one). bool StoreInCompressor(LogRecordCompressor* compressor); // Sets log message to a previous version of compressed message. // Returns false, if there is no previous message. bool RetrieveCompressedPrevious(LogRecordCompressor* compressor) { return RetrieveCompressedPrevious(compressor, ""); } // Does the same at the version without arguments, and sets a prefix. bool RetrieveCompressedPrevious(LogRecordCompressor* compressor, const char* prefix); // Write the log message to the log file currently opened. void WriteToLogFile(); // Write a null-terminated string to to the log file currently opened. void WriteCStringToLogFile(const char* str); // A handler that is called when Log::Write fails. typedef void (*WriteFailureHandler)(); static void set_write_failure_handler(WriteFailureHandler handler) { write_failure_handler = handler; } private: static WriteFailureHandler write_failure_handler; ScopedLock sl; int pos_; }; #endif // ENABLE_LOGGING_AND_PROFILING } } // namespace v8::internal #endif // V8_LOG_UTILS_H_