|
| 1 | +#include "chunks.h" |
| 2 | +#include <limits.h> |
| 3 | + |
| 4 | +#define NORMAL 0 |
| 5 | +#define HIGHLIGHTED 1 |
| 6 | + |
| 7 | +#define BUFFER_SIZE 0x10000 |
| 8 | +#define CHUNK_SIZE 0x1000 |
| 9 | +#define READ_CHUNK_MASK Q_INT64_C(0xfffffffffffff000) |
| 10 | + |
| 11 | +// ***************************************** Constructors and file settings |
| 12 | + |
| 13 | +Chunks::Chunks(QObject *parent): QObject(parent) |
| 14 | +{ |
| 15 | + QBuffer *buf = new QBuffer(this); |
| 16 | + setIODevice(*buf); |
| 17 | +} |
| 18 | + |
| 19 | +Chunks::Chunks(QIODevice &ioDevice, QObject *parent): QObject(parent) |
| 20 | +{ |
| 21 | + setIODevice(ioDevice); |
| 22 | +} |
| 23 | + |
| 24 | +bool Chunks::setIODevice(QIODevice &ioDevice) |
| 25 | +{ |
| 26 | + _ioDevice = &ioDevice; |
| 27 | + bool ok = _ioDevice->open(QIODevice::ReadOnly); |
| 28 | + if (ok) // Try to open IODevice |
| 29 | + { |
| 30 | + _size = _ioDevice->size(); |
| 31 | + _ioDevice->close(); |
| 32 | + } |
| 33 | + else // Fallback is an empty buffer |
| 34 | + { |
| 35 | + QBuffer *buf = new QBuffer(this); |
| 36 | + _ioDevice = buf; |
| 37 | + _size = 0; |
| 38 | + } |
| 39 | + _chunks.clear(); |
| 40 | + _pos = 0; |
| 41 | + return ok; |
| 42 | +} |
| 43 | + |
| 44 | + |
| 45 | +// ***************************************** Getting data out of Chunks |
| 46 | + |
| 47 | +QByteArray Chunks::data(qint64 pos, qint64 maxSize, QByteArray *highlighted) |
| 48 | +{ |
| 49 | + qint64 ioDelta = 0; |
| 50 | + int chunkIdx = 0; |
| 51 | + |
| 52 | + Chunk chunk; |
| 53 | + QByteArray buffer; |
| 54 | + |
| 55 | + // Do some checks and some arrangements |
| 56 | + if (highlighted) |
| 57 | + highlighted->clear(); |
| 58 | + |
| 59 | + if (pos >= _size) |
| 60 | + return buffer; |
| 61 | + |
| 62 | + if (maxSize < 0) |
| 63 | + maxSize = _size; |
| 64 | + else |
| 65 | + if ((pos + maxSize) > _size) |
| 66 | + maxSize = _size - pos; |
| 67 | + |
| 68 | + _ioDevice->open(QIODevice::ReadOnly); |
| 69 | + |
| 70 | + while (maxSize > 0) |
| 71 | + { |
| 72 | + chunk.absPos = LLONG_MAX; |
| 73 | + bool chunksLoopOngoing = true; |
| 74 | + while ((chunkIdx < _chunks.count()) && chunksLoopOngoing) |
| 75 | + { |
| 76 | + // In this section, we track changes before our required data and |
| 77 | + // we take the editdet data, if availible. ioDelta is a difference |
| 78 | + // counter to justify the read pointer to the original data, if |
| 79 | + // data in between was deleted or inserted. |
| 80 | + |
| 81 | + chunk = _chunks[chunkIdx]; |
| 82 | + if (chunk.absPos > pos) |
| 83 | + chunksLoopOngoing = false; |
| 84 | + else |
| 85 | + { |
| 86 | + chunkIdx += 1; |
| 87 | + qint64 count; |
| 88 | + qint64 chunkOfs = pos - chunk.absPos; |
| 89 | + if (maxSize > ((qint64)chunk.data.size() - chunkOfs)) |
| 90 | + { |
| 91 | + count = (qint64)chunk.data.size() - chunkOfs; |
| 92 | + ioDelta += CHUNK_SIZE - chunk.data.size(); |
| 93 | + } |
| 94 | + else |
| 95 | + count = maxSize; |
| 96 | + if (count > 0) |
| 97 | + { |
| 98 | + buffer += chunk.data.mid(chunkOfs, (int)count); |
| 99 | + maxSize -= count; |
| 100 | + pos += count; |
| 101 | + if (highlighted) |
| 102 | + *highlighted += chunk.dataChanged.mid(chunkOfs, (int)count); |
| 103 | + } |
| 104 | + } |
| 105 | + } |
| 106 | + |
| 107 | + if ((maxSize > 0) && (pos < chunk.absPos)) |
| 108 | + { |
| 109 | + // In this section, we read data from the original source. This only will |
| 110 | + // happen, whe no copied data is available |
| 111 | + |
| 112 | + qint64 byteCount; |
| 113 | + QByteArray readBuffer; |
| 114 | + if ((chunk.absPos - pos) > maxSize) |
| 115 | + byteCount = maxSize; |
| 116 | + else |
| 117 | + byteCount = chunk.absPos - pos; |
| 118 | + |
| 119 | + maxSize -= byteCount; |
| 120 | + _ioDevice->seek(pos + ioDelta); |
| 121 | + readBuffer = _ioDevice->read(byteCount); |
| 122 | + buffer += readBuffer; |
| 123 | + if (highlighted) |
| 124 | + *highlighted += QByteArray(readBuffer.size(), NORMAL); |
| 125 | + pos += readBuffer.size(); |
| 126 | + } |
| 127 | + } |
| 128 | + _ioDevice->close(); |
| 129 | + return buffer; |
| 130 | +} |
| 131 | + |
| 132 | +bool Chunks::write(QIODevice &iODevice, qint64 pos, qint64 count) |
| 133 | +{ |
| 134 | + if (count == -1) |
| 135 | + count = _size; |
| 136 | + bool ok = iODevice.open(QIODevice::WriteOnly); |
| 137 | + if (ok) |
| 138 | + { |
| 139 | + for (qint64 idx=pos; idx < count; idx += BUFFER_SIZE) |
| 140 | + { |
| 141 | + QByteArray ba = data(idx, BUFFER_SIZE); |
| 142 | + iODevice.write(ba); |
| 143 | + } |
| 144 | + iODevice.close(); |
| 145 | + } |
| 146 | + return ok; |
| 147 | +} |
| 148 | + |
| 149 | + |
| 150 | +// ***************************************** Set and get highlighting infos |
| 151 | + |
| 152 | +void Chunks::setDataChanged(qint64 pos, bool dataChanged) |
| 153 | +{ |
| 154 | + if ((pos < 0) || (pos >= _size)) |
| 155 | + return; |
| 156 | + int chunkIdx = getChunkIndex(pos); |
| 157 | + qint64 posInBa = pos - _chunks[chunkIdx].absPos; |
| 158 | + _chunks[chunkIdx].dataChanged[(int)posInBa] = char(dataChanged); |
| 159 | +} |
| 160 | + |
| 161 | +bool Chunks::dataChanged(qint64 pos) |
| 162 | +{ |
| 163 | + QByteArray highlighted; |
| 164 | + data(pos, 1, &highlighted); |
| 165 | + return bool(highlighted.at(0)); |
| 166 | +} |
| 167 | + |
| 168 | + |
| 169 | +// ***************************************** Search API |
| 170 | + |
| 171 | +qint64 Chunks::indexOf(const QByteArray &ba, qint64 from) |
| 172 | +{ |
| 173 | + qint64 result = -1; |
| 174 | + QByteArray buffer; |
| 175 | + |
| 176 | + for (qint64 pos=from; (pos < _size) && (result < 0); pos += BUFFER_SIZE) |
| 177 | + { |
| 178 | + buffer = data(pos, BUFFER_SIZE + ba.size() - 1); |
| 179 | + int findPos = buffer.indexOf(ba); |
| 180 | + if (findPos >= 0) |
| 181 | + result = pos + (qint64)findPos; |
| 182 | + } |
| 183 | + return result; |
| 184 | +} |
| 185 | + |
| 186 | +qint64 Chunks::lastIndexOf(const QByteArray &ba, qint64 from) |
| 187 | +{ |
| 188 | + qint64 result = -1; |
| 189 | + QByteArray buffer; |
| 190 | + |
| 191 | + for (qint64 pos=from; (pos > 0) && (result < 0); pos -= BUFFER_SIZE) |
| 192 | + { |
| 193 | + qint64 sPos = pos - BUFFER_SIZE - (qint64)ba.size() + 1; |
| 194 | + if (sPos < 0) |
| 195 | + sPos = 0; |
| 196 | + buffer = data(sPos, pos - sPos); |
| 197 | + int findPos = buffer.lastIndexOf(ba); |
| 198 | + if (findPos >= 0) |
| 199 | + result = sPos + (qint64)findPos; |
| 200 | + } |
| 201 | + return result; |
| 202 | +} |
| 203 | + |
| 204 | + |
| 205 | +// ***************************************** Char manipulations |
| 206 | + |
| 207 | +bool Chunks::insert(qint64 pos, char b) |
| 208 | +{ |
| 209 | + if ((pos < 0) || (pos > _size)) |
| 210 | + return false; |
| 211 | + int chunkIdx; |
| 212 | + if (pos == _size) |
| 213 | + chunkIdx = getChunkIndex(pos-1); |
| 214 | + else |
| 215 | + chunkIdx = getChunkIndex(pos); |
| 216 | + qint64 posInBa = pos - _chunks[chunkIdx].absPos; |
| 217 | + _chunks[chunkIdx].data.insert(posInBa, b); |
| 218 | + _chunks[chunkIdx].dataChanged.insert(posInBa, char(1)); |
| 219 | + for (int idx=chunkIdx+1; idx < _chunks.size(); idx++) |
| 220 | + _chunks[idx].absPos += 1; |
| 221 | + _size += 1; |
| 222 | + _pos = pos; |
| 223 | + return true; |
| 224 | +} |
| 225 | + |
| 226 | +bool Chunks::overwrite(qint64 pos, char b) |
| 227 | +{ |
| 228 | + if ((pos < 0) || (pos >= _size)) |
| 229 | + return false; |
| 230 | + int chunkIdx = getChunkIndex(pos); |
| 231 | + qint64 posInBa = pos - _chunks[chunkIdx].absPos; |
| 232 | + _chunks[chunkIdx].data[(int)posInBa] = b; |
| 233 | + _chunks[chunkIdx].dataChanged[(int)posInBa] = char(1); |
| 234 | + _pos = pos; |
| 235 | + return true; |
| 236 | +} |
| 237 | + |
| 238 | +bool Chunks::removeAt(qint64 pos) |
| 239 | +{ |
| 240 | + if ((pos < 0) || (pos >= _size)) |
| 241 | + return false; |
| 242 | + int chunkIdx = getChunkIndex(pos); |
| 243 | + qint64 posInBa = pos - _chunks[chunkIdx].absPos; |
| 244 | + _chunks[chunkIdx].data.remove(posInBa, 1); |
| 245 | + _chunks[chunkIdx].dataChanged.remove(posInBa, 1); |
| 246 | + for (int idx=chunkIdx+1; idx < _chunks.size(); idx++) |
| 247 | + _chunks[idx].absPos -= 1; |
| 248 | + _size -= 1; |
| 249 | + _pos = pos; |
| 250 | + return true; |
| 251 | +} |
| 252 | + |
| 253 | + |
| 254 | +// ***************************************** Utility functions |
| 255 | + |
| 256 | +char Chunks::operator[](qint64 pos) |
| 257 | +{ |
| 258 | + return data(pos, 1)[0]; |
| 259 | +} |
| 260 | + |
| 261 | +qint64 Chunks::pos() |
| 262 | +{ |
| 263 | + return _pos; |
| 264 | +} |
| 265 | + |
| 266 | +qint64 Chunks::size() |
| 267 | +{ |
| 268 | + return _size; |
| 269 | +} |
| 270 | + |
| 271 | +int Chunks::getChunkIndex(qint64 absPos) |
| 272 | +{ |
| 273 | + // This routine checks, if there is already a copied chunk available. If os, it |
| 274 | + // returns a reference to it. If there is no copied chunk available, original |
| 275 | + // data will be copied into a new chunk. |
| 276 | + |
| 277 | + int foundIdx = -1; |
| 278 | + int insertIdx = 0; |
| 279 | + qint64 ioDelta = 0; |
| 280 | + |
| 281 | + |
| 282 | + for (int idx=0; idx < _chunks.size(); idx++) |
| 283 | + { |
| 284 | + Chunk chunk = _chunks[idx]; |
| 285 | + if ((absPos >= chunk.absPos) && (absPos < (chunk.absPos + chunk.data.size()))) |
| 286 | + { |
| 287 | + foundIdx = idx; |
| 288 | + break; |
| 289 | + } |
| 290 | + if (absPos < chunk.absPos) |
| 291 | + { |
| 292 | + insertIdx = idx; |
| 293 | + break; |
| 294 | + } |
| 295 | + ioDelta += chunk.data.size() - CHUNK_SIZE; |
| 296 | + insertIdx = idx + 1; |
| 297 | + } |
| 298 | + |
| 299 | + if (foundIdx == -1) |
| 300 | + { |
| 301 | + Chunk newChunk; |
| 302 | + qint64 readAbsPos = absPos - ioDelta; |
| 303 | + qint64 readPos = (readAbsPos & READ_CHUNK_MASK); |
| 304 | + _ioDevice->open(QIODevice::ReadOnly); |
| 305 | + _ioDevice->seek(readPos); |
| 306 | + newChunk.data = _ioDevice->read(CHUNK_SIZE); |
| 307 | + _ioDevice->close(); |
| 308 | + newChunk.absPos = absPos - (readAbsPos - readPos); |
| 309 | + newChunk.dataChanged = QByteArray(newChunk.data.size(), char(0)); |
| 310 | + _chunks.insert(insertIdx, newChunk); |
| 311 | + foundIdx = insertIdx; |
| 312 | + } |
| 313 | + return foundIdx; |
| 314 | +} |
| 315 | + |
| 316 | + |
| 317 | +#ifdef MODUL_TEST |
| 318 | +int Chunks::chunkSize() |
| 319 | +{ |
| 320 | + return _chunks.size(); |
| 321 | +} |
| 322 | + |
| 323 | +#endif |
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