1 // Copyright (c) 2009 The Chromium 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 NET_TOOLS_FLIP_SERVER_BUFFER_INTERFACE_H__ 6 #define NET_TOOLS_FLIP_SERVER_BUFFER_INTERFACE_H__ 7 8 namespace net { 9 10 class BufferInterface { 11 public: 12 13 // Returns the bytes which can be read from the buffer. There is no 14 // guarantee that the bytes are contiguous. 15 virtual int ReadableBytes() const = 0; 16 17 // Summary: 18 // returns the size of this buffer 19 // Returns: 20 // size of this buffer. 21 virtual int BufferSize() const = 0; 22 23 // Summary: 24 // returns the number of bytes free in this buffer. 25 // Returns: 26 // number of bytes free. 27 virtual int BytesFree() const = 0; 28 29 // Summary: 30 // Returns true if empty. 31 // Returns: 32 // true - if empty 33 // false - otherwise 34 virtual bool Empty() const = 0; 35 36 // Summary: 37 // Returns true if the buffer is full. 38 virtual bool Full() const = 0; 39 40 // Summary: 41 // returns the number of characters written. 42 // appends up-to-'size' bytes to the buffer. 43 // Args: 44 // bytes - bytes which are read, and copied into the buffer. 45 // size - number of bytes which are read and copied. 46 // this number shall be >= 0. 47 virtual int Write(const char* bytes, int size) = 0; 48 49 // Summary: 50 // Gets a pointer which can be written to (assigned to). 51 // this pointer (and size) can be used in functions like 52 // recv() or read(), etc. 53 // If *size is zero upon returning from this function, that it 54 // is unsafe to dereference *ptr. 55 // Args: 56 // ptr - assigned a pointer to which we can write 57 // size - the amount of data (in bytes) that it is safe to write to ptr. 58 virtual void GetWritablePtr(char **ptr, int* size) const = 0; 59 60 // Summary: 61 // Gets a pointer which can be read from 62 // this pointer (and size) can be used in functions like 63 // send() or write(), etc. 64 // If *size is zero upon returning from this function, that it 65 // is unsafe to dereference *ptr. 66 // Args: 67 // ptr - assigned a pointer from which we may read 68 // size - the amount of data (in bytes) that it is safe to read 69 virtual void GetReadablePtr(char **ptr, int* size) const = 0; 70 71 // Summary: 72 // Reads bytes out of the buffer, and writes them into 'bytes'. 73 // Returns the number of bytes read. 74 // Consumes bytes from the buffer (possibly, but not necessarily 75 // rendering them free) 76 // Args: 77 // bytes - the pointer into which bytes are read from this buffer 78 // and written into 79 // size - number of bytes which are read and copied. 80 // this number shall be >= 0. 81 // Returns: 82 // the number of bytes read from 'bytes' 83 virtual int Read(char* bytes, int size) = 0; 84 85 // Summary: 86 // removes all data from the buffer 87 virtual void Clear() = 0; 88 89 // Summary: 90 // reserves contiguous writable empty space in the buffer of size bytes. 91 // Returns true if the reservation is successful. 92 // If a derive class chooses not to implement reservation, its 93 // implementation should return false. 94 virtual bool Reserve(int size) = 0; 95 96 // Summary: 97 // removes the oldest 'amount_to_consume' characters from this buffer, 98 // Args: 99 // amount_to_advance - .. this should be self-explanatory =) 100 // this number shall be >= 0. 101 virtual void AdvanceReadablePtr(int amount_to_advance) = 0; 102 103 // Summary: 104 // Moves the internal pointers around such that the 105 // amount of data specified here is expected to 106 // already be resident (as if it was Written) 107 // Args: 108 // amount_to_advance - self explanatory. 109 // this number shall be >= 0. 110 virtual void AdvanceWritablePtr(int amount_to_advance) = 0; 111 112 virtual ~BufferInterface() {} 113 114 protected: 115 BufferInterface() {} 116 }; 117 118 } // namespace net 119 120 #endif // NET_TOOLS_FLIP_SERVER_BUFFER_INTERFACE__H__ 121 122
