1 // Copyright 2015 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROMIUMOS_WIDE_PROFILING_DATA_WRITER_H_ 6 #define CHROMIUMOS_WIDE_PROFILING_DATA_WRITER_H_ 7 8 #include <stddef.h> 9 10 #include "compat/string.h" 11 12 namespace quipper { 13 14 // Interface for writing data to a destination. The nature of the destination is 15 // unspecified, and is to be specified by derived classes. 16 class DataWriter { 17 public: 18 virtual ~DataWriter() {} 19 20 // Moves the data pointer to |offset| bytes from the beginning of the data. 21 virtual void SeekSet(size_t offset) = 0; 22 23 // Returns the position of the data pointer, in bytes from the beginning of 24 // the data. 25 virtual size_t Tell() const = 0; 26 27 virtual size_t size() const { return size_; } 28 29 // Writes raw data. Returns true if it managed to write |size| bytes. 30 virtual bool WriteData(const void* src, const size_t size) = 0; 31 32 // Like WriteData(), but prints an error if it doesn't write all |size| bytes. 33 virtual bool WriteDataValue(const void* src, const size_t size, 34 const string& value_name); 35 36 // Writes a string. If the string length is smaller than |size|, it will fill 37 // in the remainder of of the destination memory with zeroes. If the string is 38 // longer than |size|, it will truncate the string, and will not add a null 39 // terminator. Returns true iff the expected number of bytes were written. 40 virtual bool WriteString(const string& str, const size_t size) = 0; 41 42 // Writes a string |src| to data, prefixed with a 32-bit size field. The size 43 // is rounded up to the next multiple of uint64. 44 bool WriteStringWithSizeToData(const string& src); 45 46 protected: 47 // Returns true if |data_size| bytes of data can be written to the current 48 // underlying destination. 49 virtual bool CanWriteSize(size_t data_size) = 0; 50 51 // Current data size. 52 size_t size_; 53 }; 54 55 } // namespace quipper 56 57 #endif // CHROMIUMOS_WIDE_PROFILING_DATA_WRITER_H_ 58
