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39
40#ifndef QRINGBUFFER_P_H
41#define QRINGBUFFER_P_H
42
43//
44// W A R N I N G
45// -------------
46//
47// This file is not part of the Qt API. It exists for the convenience
48// of a number of Qt sources files. This header file may change from
49// version to version without notice, or even be removed.
50//
51// We mean it.
52//
53
54#include <QtCore/private/qglobal_p.h>
55#include <QtCore/qbytearray.h>
56#include <QtCore/qlist.h>
57
58QT_BEGIN_NAMESPACE
59
60#ifndef QRINGBUFFER_CHUNKSIZE
61#define QRINGBUFFER_CHUNKSIZE 4096
62#endif
63
64class QRingChunk
65{
66public:
67 // initialization and cleanup
68 inline QRingChunk() noexcept :
69 headOffset(0), tailOffset(0)
70 {
71 }
72 inline QRingChunk(const QRingChunk &other) noexcept :
73 chunk(other.chunk), headOffset(other.headOffset), tailOffset(other.tailOffset)
74 {
75 }
76 explicit inline QRingChunk(int alloc) :
77 chunk(alloc, Qt::Uninitialized), headOffset(0), tailOffset(0)
78 {
79 }
80 explicit inline QRingChunk(const QByteArray &qba) noexcept :
81 chunk(qba), headOffset(0), tailOffset(qba.size())
82 {
83 }
84
85 inline QRingChunk &operator=(const QRingChunk &other) noexcept
86 {
87 chunk = other.chunk;
88 headOffset = other.headOffset;
89 tailOffset = other.tailOffset;
90 return *this;
91 }
92 inline QRingChunk(QRingChunk &&other) noexcept :
93 chunk(other.chunk), headOffset(other.headOffset), tailOffset(other.tailOffset)
94 {
95 other.headOffset = other.tailOffset = 0;
96 }
97 QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QRingChunk)
98
99 inline void swap(QRingChunk &other) noexcept
100 {
101 chunk.swap(other.chunk);
102 qSwap(headOffset, other.headOffset);
103 qSwap(tailOffset, other.tailOffset);
104 }
105
106 // allocating and sharing
107 void allocate(int alloc);
108 inline bool isShared() const
109 {
110 return !chunk.isDetached();
111 }
112 Q_CORE_EXPORT void detach();
113 QByteArray toByteArray();
114
115 // getters
116 inline int head() const
117 {
118 return headOffset;
119 }
120 inline int size() const
121 {
122 return tailOffset - headOffset;
123 }
124 inline int capacity() const
125 {
126 return chunk.size();
127 }
128 inline int available() const
129 {
130 return chunk.size() - tailOffset;
131 }
132 inline const char *data() const
133 {
134 return chunk.constData() + headOffset;
135 }
136 inline char *data()
137 {
138 if (isShared())
139 detach();
140 return chunk.data() + headOffset;
141 }
142
143 // array management
144 inline void advance(int offset)
145 {
146 Q_ASSERT(headOffset + offset >= 0);
147 Q_ASSERT(size() - offset > 0);
148
149 headOffset += offset;
150 }
151 inline void grow(int offset)
152 {
153 Q_ASSERT(size() + offset > 0);
154 Q_ASSERT(head() + size() + offset <= capacity());
155
156 tailOffset += offset;
157 }
158 inline void assign(const QByteArray &qba)
159 {
160 chunk = qba;
161 headOffset = 0;
162 tailOffset = qba.size();
163 }
164 inline void reset()
165 {
166 headOffset = tailOffset = 0;
167 }
168 inline void clear()
169 {
170 assign(QByteArray());
171 }
172
173private:
174 QByteArray chunk;
175 int headOffset, tailOffset;
176};
177
178class QRingBuffer
179{
180public:
181 explicit inline QRingBuffer(int growth = QRINGBUFFER_CHUNKSIZE) :
182 bufferSize(0), basicBlockSize(growth) { }
183
184 inline void setChunkSize(int size) {
185 basicBlockSize = size;
186 }
187
188 inline int chunkSize() const {
189 return basicBlockSize;
190 }
191
192 inline qint64 nextDataBlockSize() const {
193 return bufferSize == 0 ? Q_INT64_C(0) : buffers.first().size();
194 }
195
196 inline const char *readPointer() const {
197 return bufferSize == 0 ? nullptr : buffers.first().data();
198 }
199
200 Q_CORE_EXPORT const char *readPointerAtPosition(qint64 pos, qint64 &length) const;
201 Q_CORE_EXPORT void free(qint64 bytes);
202 Q_CORE_EXPORT char *reserve(qint64 bytes);
203 Q_CORE_EXPORT char *reserveFront(qint64 bytes);
204
205 inline void truncate(qint64 pos) {
206 Q_ASSERT(pos >= 0 && pos <= size());
207
208 chop(size() - pos);
209 }
210
211 Q_CORE_EXPORT void chop(qint64 bytes);
212
213 inline bool isEmpty() const {
214 return bufferSize == 0;
215 }
216
217 inline int getChar() {
218 if (isEmpty())
219 return -1;
220 char c = *readPointer();
221 free(1);
222 return int(uchar(c));
223 }
224
225 inline void putChar(char c) {
226 char *ptr = reserve(1);
227 *ptr = c;
228 }
229
230 void ungetChar(char c)
231 {
232 char *ptr = reserveFront(1);
233 *ptr = c;
234 }
235
236
237 inline qint64 size() const {
238 return bufferSize;
239 }
240
241 Q_CORE_EXPORT void clear();
242 inline qint64 indexOf(char c) const { return indexOf(c, size()); }
243 Q_CORE_EXPORT qint64 indexOf(char c, qint64 maxLength, qint64 pos = 0) const;
244 Q_CORE_EXPORT qint64 read(char *data, qint64 maxLength);
245 Q_CORE_EXPORT QByteArray read();
246 Q_CORE_EXPORT qint64 peek(char *data, qint64 maxLength, qint64 pos = 0) const;
247 Q_CORE_EXPORT void append(const char *data, qint64 size);
248 Q_CORE_EXPORT void append(const QByteArray &qba);
249
250 inline qint64 skip(qint64 length) {
251 qint64 bytesToSkip = qMin(length, bufferSize);
252
253 free(bytesToSkip);
254 return bytesToSkip;
255 }
256
257 Q_CORE_EXPORT qint64 readLine(char *data, qint64 maxLength);
258
259 inline bool canReadLine() const {
260 return indexOf('\n') >= 0;
261 }
262
263private:
264 QList<QRingChunk> buffers;
265 qint64 bufferSize;
266 int basicBlockSize;
267};
268
269Q_DECLARE_SHARED(QRingChunk)
270Q_DECLARE_TYPEINFO(QRingBuffer, Q_MOVABLE_TYPE);
271
272QT_END_NAMESPACE
273
274#endif // QRINGBUFFER_P_H
275