1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
// ByteStream.h
// Interfaces to the cByteBuffer class representing a ringbuffer of bytes
#pragma once
// fwd:
class cUUID;
/** An object that can store incoming bytes and lets its clients read the bytes sequentially
The bytes are stored in a ringbuffer of constant size; if more than that size
is requested, the write operation fails.
The bytes stored can be retrieved using various ReadXXX functions; these assume that the needed
number of bytes are present in the buffer (ASSERT; for performance reasons).
The reading doesn't actually remove the bytes, it only moves the internal read ptr.
To remove the bytes, call CommitRead().
To re-start reading from the beginning, call ResetRead().
This class doesn't implement thread safety, the clients of this class need to provide
their own synchronization.
*/
class cByteBuffer
{
public:
cByteBuffer(size_t a_BufferSize);
~cByteBuffer();
/** Writes the bytes specified to the ringbuffer. Returns true if successful, false if not */
bool Write(const void * a_Bytes, size_t a_Count);
/** Returns the number of bytes that can be successfully written to the ringbuffer */
size_t GetFreeSpace(void) const;
/** Returns the number of bytes that are currently in the ringbuffer. Note GetReadableBytes() */
size_t GetUsedSpace(void) const;
/** Returns the number of bytes that are currently available for reading (may be less than UsedSpace due to some data having been read already) */
size_t GetReadableSpace(void) const;
/** Returns the current data start index. For debugging purposes. */
size_t GetDataStart(void) const { return m_DataStart; }
/** Returns if the given value can fit in a protocol big-endian 8 bit integer. */
static bool CanBEInt8Represent(int a_Value);
/** Returns if the given value can fit in a protocol big-endian 16 bit integer. */
static bool CanBEInt16Represent(int a_Value);
/** Returns true if the specified amount of bytes are available for reading */
bool CanReadBytes(size_t a_Count) const;
/** Returns true if the specified amount of bytes are available for writing */
bool CanWriteBytes(size_t a_Count) const;
// Read the specified datatype and advance the read pointer; return true if successfully read:
bool ReadBEInt8 (Int8 & a_Value);
bool ReadBEInt16 (Int16 & a_Value);
bool ReadBEInt32 (Int32 & a_Value);
bool ReadBEInt64 (Int64 & a_Value);
bool ReadBEUInt8 (UInt8 & a_Value);
bool ReadBEUInt16 (UInt16 & a_Value);
bool ReadBEUInt32 (UInt32 & a_Value);
bool ReadBEUInt64 (UInt64 & a_Value);
bool ReadBEFloat (float & a_Value);
bool ReadBEDouble (double & a_Value);
bool ReadBool (bool & a_Value);
bool ReadVarInt32 (UInt32 & a_Value);
bool ReadVarInt64 (UInt64 & a_Value);
bool ReadVarUTF8String (AString & a_Value); // string length as VarInt, then string as UTF-8
bool ReadLEInt (int & a_Value);
bool ReadXYZPosition64 (int & a_BlockX, int & a_BlockY, int & a_BlockZ);
bool ReadXYZPosition64 (Vector3i & a_Position);
bool ReadXZYPosition64 (int & a_BlockX, int & a_BlockY, int & a_BlockZ);
bool ReadXZYPosition64 (Vector3i & a_Position);
bool ReadUUID (cUUID & a_Value);
/** Reads VarInt, assigns it to anything that can be assigned from an UInt64 (unsigned short, char, Byte, double, ...) */
template <typename T> bool ReadVarInt(T & a_Value)
{
UInt64 v;
bool res = ReadVarInt64(v);
if (res)
{
a_Value = static_cast<T>(v);
}
return res;
}
// Write the specified datatype; return true if successfully written
bool WriteBEInt8 (Int8 a_Value);
bool WriteBEInt8 (std::byte a_Value);
bool WriteBEInt16 (Int16 a_Value);
bool WriteBEInt32 (Int32 a_Value);
bool WriteBEInt64 (Int64 a_Value);
bool WriteBEUInt8 (UInt8 a_Value);
bool WriteBEUInt16 (UInt16 a_Value);
bool WriteBEUInt32 (UInt32 a_Value);
bool WriteBEUInt64 (UInt64 a_Value);
bool WriteBEFloat (float a_Value);
bool WriteBEDouble (double a_Value);
bool WriteBool (bool a_Value);
bool WriteVarInt32 (UInt32 a_Value);
bool WriteVarInt64 (UInt64 a_Value);
bool WriteVarUTF8String (const AString & a_Value); // string length as VarInt, then string as UTF-8
bool WriteLEInt32 (Int32 a_Value);
bool WriteXYZPosition64 (Int32 a_BlockX, Int32 a_BlockY, Int32 a_BlockZ);
bool WriteXZYPosition64 (Int32 a_BlockX, Int32 a_BlockY, Int32 a_BlockZ);
/** Reads a_Count bytes into a_Buffer; returns true if successful */
bool ReadBuf(void * a_Buffer, size_t a_Count);
/** Writes a_Count bytes into a_Buffer; returns true if successful */
bool WriteBuf(const void * a_Buffer, size_t a_Count);
/** Writes a_Count bytes into a_Buffer; returns true if successful */
bool WriteBuf(size_t a_Count, unsigned char a_Value);
/** Reads a_Count bytes into a_String; returns true if successful */
bool ReadSome(ContiguousByteBuffer & a_String, size_t a_Count);
/** Skips reading by a_Count bytes; returns false if not enough bytes in the ringbuffer */
bool SkipRead(size_t a_Count);
/** Reads all available data into a_Data */
void ReadAll(ContiguousByteBuffer & a_Data);
/** Reads the specified number of bytes and writes it into the destinatio bytebuffer. Returns true on success. */
bool ReadToByteBuffer(cByteBuffer & a_Dst, size_t a_NumBytes);
/** Removes the bytes that have been read from the ringbuffer */
void CommitRead(void);
/** Restarts next reading operation at the start of the ringbuffer */
void ResetRead(void);
/** Re-reads the data that has been read since the last commit to the current readpos. Used by ProtoProxy to duplicate communication */
void ReadAgain(ContiguousByteBuffer & a_Out);
/** Checks if the internal state is valid (read and write positions in the correct bounds) using ASSERTs */
void CheckValid(void) const;
/** Gets the number of bytes that are needed to represent the given VarInt */
static size_t GetVarIntSize(UInt32 a_Value);
protected:
std::byte * m_Buffer;
size_t m_BufferSize; // Total size of the ringbuffer
size_t m_DataStart; // Where the data starts in the ringbuffer
size_t m_WritePos; // Where the data ends in the ringbuffer
size_t m_ReadPos; // Where the next read will start in the ringbuffer
#ifndef NDEBUG
/** The ID of the thread currently accessing the object.
Used for checking that only one thread accesses the object at a time, via cSingleThreadAccessChecker. */
mutable std::thread::id m_ThreadID;
#endif
/** Advances the m_ReadPos by a_Count bytes */
void AdvanceReadPos(size_t a_Count);
} ;
|
