| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.iapi.services.io.CompressedNumber |
| 4 | |
| 5 | Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.iapi.services.io; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 24 | |
| 25 | import java.io.*; |
| 26 | |
| 27 | /** |
| 28 | Static methods to write and read compressed forms of numbers |
| 29 | to DataOut and DataIn interfaces. Format written is platform |
| 30 | independent like the Data* interfaces and must remain fixed |
| 31 | once a product is shipped. If a different format is required |
| 32 | then write a new set of methods, e.g. writeInt2. The formats |
| 33 | defined by stored format identifiers are implicitly dependent |
| 34 | on these formats not changing. |
| 35 | */ |
| 36 | |
| 37 | public abstract class CompressedNumber { |
| 38 | |
| 39 | // the maximum number of bytes written out for an int |
| 40 | public static final int MAX_INT_STORED_SIZE = 4; |
| 41 | |
| 42 | // the maximum number of bytes written out for a long |
| 43 | public static final int MAX_LONG_STORED_SIZE = 8; |
| 44 | |
| 45 | // largest int stored compressed in 1 byte |
| 46 | public static final int MAX_COMPRESSED_INT_ONE_BYTE = 0x3f; |
| 47 | |
| 48 | // largest int stored compressed in 2 bytes |
| 49 | public static final int MAX_COMPRESSED_INT_TWO_BYTES = 0x3fff; |
| 50 | |
| 51 | |
| 52 | /** |
| 53 | Write a compressed integer only supporting signed values. |
| 54 | Formats are (with x representing value bits): |
| 55 | <PRE> |
| 56 | 1 Byte - 00xxxxxx Represents the value <= 63 (0x3f) |
| 57 | 2 Byte - 01xxxxxx xxxxxxxx Represents the value > 63 && <= 16383 (0x3fff) |
| 58 | 4 byte - 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Represents the value > 16383 && <= MAX_INT |
| 59 | </PRE> |
| 60 | |
| 61 | |
| 62 | @exception IOException value is negative or an exception was thrown by a method on out. |
| 63 | */ |
| 64 | public static final int writeInt(DataOutput out, int value) throws IOException { |
| 65 | |
| 66 | if (value < 0) |
| 67 | throw new IOException(); |
| 68 | |
| 69 | if (value <= 0x3f) { |
| 70 | |
| 71 | out.writeByte(value); |
| 72 | return 1; |
| 73 | } |
| 74 | |
| 75 | if (value <= 0x3fff) { |
| 76 | |
| 77 | out.writeByte(0x40 | (value >>> 8)); |
| 78 | out.writeByte(value & 0xff); |
| 79 | return 2; |
| 80 | } |
| 81 | |
| 82 | out.writeByte(((value >>> 24) | 0x80) & 0xff); |
| 83 | out.writeByte((value >>> 16) & 0xff); |
| 84 | out.writeByte((value >>> 8) & 0xff); |
| 85 | out.writeByte((value) & 0xff); |
| 86 | return 4; |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | Write a compressed integer directly to an OutputStream. |
| 91 | @exception IOException an exception was thrown by a method on in. |
| 92 | */ |
| 93 | public static final int writeInt(OutputStream out, int value) throws IOException { |
| 94 | |
| 95 | if (value < 0) |
| 96 | throw new IOException(); |
| 97 | |
| 98 | if (value <= 0x3f) { |
| 99 | |
| 100 | out.write(value); |
| 101 | return 1; |
| 102 | } |
| 103 | |
| 104 | if (value <= 0x3fff) { |
| 105 | |
| 106 | out.write(0x40 | (value >>> 8)); |
| 107 | out.write(value & 0xff); |
| 108 | return 2; |
| 109 | } |
| 110 | |
| 111 | out.write(((value >>> 24) | 0x80) & 0xff); |
| 112 | out.write((value >>> 16) & 0xff); |
| 113 | out.write((value >>> 8) & 0xff); |
| 114 | out.write((value) & 0xff); |
| 115 | return 4; |
| 116 | } |
| 117 | |
| 118 | |
| 119 | /** |
| 120 | Read an integer previously written by writeInt(). |
| 121 | |
| 122 | @exception IOException an exception was thrown by a method on in. |
| 123 | */ |
| 124 | public static final int readInt(DataInput in) throws IOException { |
| 125 | |
| 126 | int value = in.readUnsignedByte(); |
| 127 | |
| 128 | if ((value & ~0x3f) == 0) |
| 129 | { |
| 130 | // length is stored in this byte, we also know that the 0x80 bit |
| 131 | // was not set, so no need to mask off the sign extension from |
| 132 | // the byte to int conversion. |
| 133 | |
| 134 | // account for 1 byte stored length of field + 1 for all returns |
| 135 | return(value); |
| 136 | } |
| 137 | else if ((value & 0x80) == 0) |
| 138 | { |
| 139 | // length is stored in 2 bytes. only use low 6 bits from 1st byte. |
| 140 | |
| 141 | if (SanityManager.DEBUG) |
| 142 | { |
| 143 | SanityManager.ASSERT((value & 0x40) == 0x40); |
| 144 | } |
| 145 | |
| 146 | // top 8 bits of 2 byte length is stored in this byte, we also |
| 147 | // know that the 0x80 bit was not set, so no need to mask off the |
| 148 | // sign extension from the 1st byte to int conversion. Need to |
| 149 | // mask the byte in data[offset + 1] to account for possible sign |
| 150 | // extension. |
| 151 | |
| 152 | return(((value & 0x3f) << 8) | in.readUnsignedByte()); |
| 153 | } |
| 154 | else |
| 155 | { |
| 156 | // length is stored in 4 bytes. only use low 7 bits from 1st byte. |
| 157 | |
| 158 | if (SanityManager.DEBUG) |
| 159 | { |
| 160 | SanityManager.ASSERT((value & 0x80) == 0x80); |
| 161 | } |
| 162 | |
| 163 | // top 8 bits of 4 byte length is stored in this byte, we also |
| 164 | // know that the 0x80 bit was set, so need to mask off the |
| 165 | // sign extension from the 1st byte to int conversion. Need to |
| 166 | // mask the bytes from the next 3 bytes data[offset + 1,2,3] to |
| 167 | // account for possible sign extension. |
| 168 | // |
| 169 | return( |
| 170 | ((value & 0x7f) << 24) | |
| 171 | (in.readUnsignedByte() << 16) | |
| 172 | (in.readUnsignedByte() << 8) | |
| 173 | (in.readUnsignedByte() )); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | Read an integer previously written by writeInt(). |
| 179 | |
| 180 | @exception IOException an exception was thrown by a method on in. |
| 181 | */ |
| 182 | public static final int readInt(InputStream in) throws IOException { |
| 183 | |
| 184 | int value = InputStreamUtil.readUnsignedByte(in); |
| 185 | |
| 186 | if ((value & ~0x3f) == 0) |
| 187 | { |
| 188 | return(value); |
| 189 | } |
| 190 | else if ((value & 0x80) == 0) |
| 191 | { |
| 192 | return( |
| 193 | ((value & 0x3f) << 8) | InputStreamUtil.readUnsignedByte(in)); |
| 194 | } |
| 195 | else |
| 196 | { |
| 197 | return( |
| 198 | ((value & 0x7f) << 24) | |
| 199 | (InputStreamUtil.readUnsignedByte(in) << 16) | |
| 200 | (InputStreamUtil.readUnsignedByte(in) << 8) | |
| 201 | (InputStreamUtil.readUnsignedByte(in) )); |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | public static final int readInt( |
| 206 | byte[] data, |
| 207 | int offset) |
| 208 | { |
| 209 | int value = data[offset++]; |
| 210 | |
| 211 | if ((value & ~0x3f) == 0) |
| 212 | { |
| 213 | // length is stored in this byte, we also know that the 0x80 bit |
| 214 | // was not set, so no need to mask off the sign extension from |
| 215 | // the byte to int conversion. |
| 216 | |
| 217 | return(value); |
| 218 | } |
| 219 | else if ((value & 0x80) == 0) |
| 220 | { |
| 221 | // length is stored in 2 bytes. only use low 6 bits from 1st byte. |
| 222 | |
| 223 | if (SanityManager.DEBUG) |
| 224 | { |
| 225 | SanityManager.ASSERT((value & 0x40) == 0x40); |
| 226 | } |
| 227 | |
| 228 | // top 8 bits of 2 byte length is stored in this byte, we also |
| 229 | // know that the 0x80 bit was not set, so no need to mask off the |
| 230 | // sign extension from the 1st byte to int conversion. Need to |
| 231 | // mask the byte in data[offset + 1] to account for possible sign |
| 232 | // extension. |
| 233 | |
| 234 | return(((value & 0x3f) << 8) | (data[offset] & 0xff)); |
| 235 | } |
| 236 | else |
| 237 | { |
| 238 | // length is stored in 4 bytes. only use low 7 bits from 1st byte. |
| 239 | |
| 240 | if (SanityManager.DEBUG) |
| 241 | { |
| 242 | SanityManager.ASSERT((value & 0x80) == 0x80); |
| 243 | } |
| 244 | |
| 245 | // top 8 bits of 4 byte length is stored in this byte, we also |
| 246 | // know that the 0x80 bit was set, so need to mask off the |
| 247 | // sign extension from the 1st byte to int conversion. Need to |
| 248 | // mask the bytes from the next 3 bytes data[offset + 1,2,3] to |
| 249 | // account for possible sign extension. |
| 250 | // |
| 251 | return( |
| 252 | ((value & 0x7f) << 24) | |
| 253 | ((data[offset++] & 0xff) << 16) | |
| 254 | ((data[offset++] & 0xff) << 8) | |
| 255 | ((data[offset] & 0xff) )); |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * Return the compressed Int value + stored size of the length + 1 |
| 261 | * <p> |
| 262 | * Given offset in array to beginning of compressed int, return the |
| 263 | * value of the compressed int + the number of bytes used to store the |
| 264 | * length. |
| 265 | * <p> |
| 266 | * So 1 byte lengths will return: length + 1 + 1 |
| 267 | * So 2 byte lengths will return: length + 2 + 1 |
| 268 | * So 4 byte lengths will return: length + 4 + 1 |
| 269 | * <p> |
| 270 | * Note that this routine will not work for lengths MAX_INT - (MAX_INT - 5). |
| 271 | * <p> |
| 272 | * This routine is currently used by the StorePage code to skip fields |
| 273 | * as efficiently as possible. Since the page size is less than |
| 274 | * (MAX_INT - 5) it is all right to use this routine. |
| 275 | * |
| 276 | * @return compressed int value + length used to store the length. |
| 277 | * |
| 278 | * @param data byte array containing the field. |
| 279 | * @param offset offset to beginning of field, ie. data[offset] contains |
| 280 | * 1st byte of the compressed int. |
| 281 | **/ |
| 282 | public static final int readIntAndReturnIntPlusOverhead( |
| 283 | byte[] data, |
| 284 | int offset) |
| 285 | { |
| 286 | int value = data[offset]; |
| 287 | |
| 288 | if ((value & ~0x3f) == 0) |
| 289 | { |
| 290 | // length is stored in this byte, we also know that the 0x80 bit |
| 291 | // was not set, so no need to mask off the sign extension from |
| 292 | // the byte to int conversion. |
| 293 | |
| 294 | // account for 1 byte stored length of field + 1 for all returns |
| 295 | return(value + 2); |
| 296 | } |
| 297 | else if ((value & 0x80) == 0) |
| 298 | { |
| 299 | // length is stored in 2 bytes. only use low 6 bits from 1st byte. |
| 300 | |
| 301 | if (SanityManager.DEBUG) |
| 302 | { |
| 303 | SanityManager.ASSERT((value & 0x40) == 0x40); |
| 304 | } |
| 305 | |
| 306 | // top 8 bits of 2 byte length is stored in this byte, we also |
| 307 | // know that the 0x80 bit was not set, so no need to mask off the |
| 308 | // sign extension from the 1st byte to int conversion. Need to |
| 309 | // mask the byte in data[offset + 1] to account for possible sign |
| 310 | // extension. |
| 311 | |
| 312 | // add 3 to account for 2 byte length + 1 added to all returns |
| 313 | |
| 314 | return((((value & 0x3f) << 8) | (data[offset + 1] & 0xff)) + 3); |
| 315 | } |
| 316 | else |
| 317 | { |
| 318 | // length is stored in 4 bytes. only use low 7 bits from 1st byte. |
| 319 | |
| 320 | if (SanityManager.DEBUG) |
| 321 | { |
| 322 | SanityManager.ASSERT((value & 0x80) == 0x80); |
| 323 | } |
| 324 | |
| 325 | // top 8 bits of 4 byte length is stored in this byte, we also |
| 326 | // know that the 0x80 bit was set, so need to mask off the |
| 327 | // sign extension from the 1st byte to int conversion. Need to |
| 328 | // mask the bytes from the next 3 bytes data[offset + 1,2,3] to |
| 329 | // account for possible sign extension. |
| 330 | |
| 331 | |
| 332 | // add 5 to account for 4 byte length + 1 added to all returns |
| 333 | return( |
| 334 | (((value & 0x7f) << 24) | |
| 335 | ((data[offset + 1] & 0xff) << 16) | |
| 336 | ((data[offset + 2] & 0xff) << 8) | |
| 337 | (data[offset + 3] & 0xff)) + 5); |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | |
| 342 | /** |
| 343 | Skip an integer previously written by writeInt(). |
| 344 | |
| 345 | @exception IOException an exception was thrown by a method on in. |
| 346 | */ |
| 347 | public static final int skipInt(DataInput in) throws IOException { |
| 348 | |
| 349 | int value = in.readUnsignedByte(); |
| 350 | |
| 351 | if ((value & 0x80) == 0x80) { |
| 352 | in.skipBytes(3); |
| 353 | return 4; |
| 354 | } |
| 355 | |
| 356 | if ((value & 0x40) == 0x40) { |
| 357 | in.skipBytes(1); |
| 358 | return 2; |
| 359 | } |
| 360 | |
| 361 | return 1; |
| 362 | } |
| 363 | |
| 364 | /** |
| 365 | Skip an integer previously written by writeInt(). |
| 366 | |
| 367 | @exception IOException an exception was thrown by a method on in. |
| 368 | */ |
| 369 | public static final int skipInt(InputStream in) throws IOException { |
| 370 | |
| 371 | int value = InputStreamUtil.readUnsignedByte(in); |
| 372 | |
| 373 | int skipBytes = 0; |
| 374 | |
| 375 | if ((value & 0x80) == 0x80) { |
| 376 | skipBytes = 3; |
| 377 | } |
| 378 | else if ((value & 0x40) == 0x40) { |
| 379 | skipBytes = 1; |
| 380 | } |
| 381 | |
| 382 | if (skipBytes != 0) { |
| 383 | if (in.skip(skipBytes) != skipBytes) |
| 384 | throw new EOFException(); |
| 385 | } |
| 386 | |
| 387 | |
| 388 | return skipBytes + 1; |
| 389 | } |
| 390 | |
| 391 | /** |
| 392 | Return the number of bytes that would be written by a writeInt call |
| 393 | */ |
| 394 | public static final int sizeInt(int value) { |
| 395 | if (value <= 0x3f) { |
| 396 | return 1; |
| 397 | } |
| 398 | if (value <= 0x3fff) { |
| 399 | return 2; |
| 400 | } |
| 401 | return 4; |
| 402 | } |
| 403 | |
| 404 | /** |
| 405 | Write a compressed long only supporting signed values. |
| 406 | |
| 407 | Formats are (with x representing value bits): |
| 408 | <PRE> |
| 409 | 2 byte - 00xxxxxx xxxxxxxx Represents the value <= 16383 (0x3fff) |
| 410 | 4 byte - 01xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Represents the value > 16383 && <= 0x3fffffff |
| 411 | 8 byte - 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Represents the value > 0x3fffffff && <= MAX_LONG |
| 412 | </PRE> |
| 413 | |
| 414 | |
| 415 | @exception IOException value is negative or an exception was thrown by a method on out. |
| 416 | */ |
| 417 | public static final int writeLong(DataOutput out, long value) throws IOException { |
| 418 | |
| 419 | if (value < 0) |
| 420 | throw new IOException(); |
| 421 | |
| 422 | if (value <= 0x3fff) { |
| 423 | |
| 424 | out.writeByte((int) ((value >>> 8) & 0xff)); |
| 425 | out.writeByte((int) ((value ) & 0xff)); |
| 426 | return 2; |
| 427 | } |
| 428 | |
| 429 | if (value <= 0x3fffffff) { |
| 430 | |
| 431 | out.writeByte((int) (((value >>> 24) | 0x40) & 0xff)); |
| 432 | out.writeByte((int) ( (value >>> 16) & 0xff)); |
| 433 | out.writeByte((int) ( (value >>> 8) & 0xff)); |
| 434 | out.writeByte((int) ( (value ) & 0xff)); |
| 435 | return 4; |
| 436 | } |
| 437 | |
| 438 | out.writeByte((int) (((value >>> 56) | 0x80) & 0xff)); |
| 439 | out.writeByte((int) ( (value >>> 48) & 0xff)); |
| 440 | out.writeByte((int) ( (value >>> 40) & 0xff)); |
| 441 | out.writeByte((int) ( (value >>> 32) & 0xff)); |
| 442 | out.writeByte((int) ( (value >>> 24) & 0xff)); |
| 443 | out.writeByte((int) ( (value >>> 16) & 0xff)); |
| 444 | out.writeByte((int) ( (value >>> 8) & 0xff)); |
| 445 | out.writeByte((int) ( (value ) & 0xff)); |
| 446 | return 8; |
| 447 | } |
| 448 | /** |
| 449 | Write a compressed integer only supporting signed values. |
| 450 | |
| 451 | @exception IOException value is negative or an exception was thrown by a method on out. |
| 452 | */ |
| 453 | public static final int writeLong(OutputStream out, long value) throws IOException { |
| 454 | |
| 455 | if (value < 0) |
| 456 | throw new IOException(); |
| 457 | |
| 458 | if (value <= 0x3fff) { |
| 459 | |
| 460 | out.write((int) ((value >>> 8) & 0xff)); |
| 461 | out.write((int) ((value ) & 0xff)); |
| 462 | return 2; |
| 463 | } |
| 464 | |
| 465 | if (value <= 0x3fffffff) { |
| 466 | |
| 467 | out.write((int) (((value >>> 24) | 0x40) & 0xff)); |
| 468 | out.write((int) ( (value >>> 16) & 0xff)); |
| 469 | out.write((int) ( (value >>> 8) & 0xff)); |
| 470 | out.write((int) ( (value ) & 0xff)); |
| 471 | return 4; |
| 472 | } |
| 473 | |
| 474 | out.write((int) (((value >>> 56) | 0x80) & 0xff)); |
| 475 | out.write((int) ( (value >>> 48) & 0xff)); |
| 476 | out.write((int) ( (value >>> 40) & 0xff)); |
| 477 | out.write((int) ( (value >>> 32) & 0xff)); |
| 478 | out.write((int) ( (value >>> 24) & 0xff)); |
| 479 | out.write((int) ( (value >>> 16) & 0xff)); |
| 480 | out.write((int) ( (value >>> 8) & 0xff)); |
| 481 | out.write((int) ( (value ) & 0xff)); |
| 482 | return 8; |
| 483 | } |
| 484 | |
| 485 | /** |
| 486 | Read a long previously written by writeLong(). |
| 487 | |
| 488 | @exception IOException an exception was thrown by a method on in. |
| 489 | */ |
| 490 | public static final long readLong(DataInput in) throws IOException { |
| 491 | |
| 492 | int int_value = in.readUnsignedByte(); |
| 493 | |
| 494 | if ((int_value & ~0x3f) == 0) |
| 495 | { |
| 496 | // test for small case first - assuming this is usual case. |
| 497 | // this is stored in 2 bytes. |
| 498 | |
| 499 | return((int_value << 8) | in.readUnsignedByte()); |
| 500 | } |
| 501 | else if ((int_value & 0x80) == 0) |
| 502 | { |
| 503 | // value is stored in 4 bytes. only use low 6 bits from 1st byte. |
| 504 | |
| 505 | return( |
| 506 | ((int_value & 0x3f) << 24) | |
| 507 | (in.readUnsignedByte() << 16) | |
| 508 | (in.readUnsignedByte() << 8) | |
| 509 | (in.readUnsignedByte())); |
| 510 | } |
| 511 | else |
| 512 | { |
| 513 | // value is stored in 8 bytes. only use low 7 bits from 1st byte. |
| 514 | return( |
| 515 | (((long) (int_value & 0x7f) ) << 56) | |
| 516 | (((long) in.readUnsignedByte()) << 48) | |
| 517 | (((long) in.readUnsignedByte()) << 40) | |
| 518 | (((long) in.readUnsignedByte()) << 32) | |
| 519 | (((long) in.readUnsignedByte()) << 24) | |
| 520 | (((long) in.readUnsignedByte()) << 16) | |
| 521 | (((long) in.readUnsignedByte()) << 8) | |
| 522 | (((long) in.readUnsignedByte()) )); |
| 523 | } |
| 524 | } |
| 525 | |
| 526 | /** |
| 527 | Read a long previously written by writeLong(). |
| 528 | |
| 529 | @exception IOException an exception was thrown by a method on in. |
| 530 | */ |
| 531 | public static final long readLong(InputStream in) throws IOException { |
| 532 | |
| 533 | int int_value = InputStreamUtil.readUnsignedByte(in); |
| 534 | |
| 535 | if ((int_value & ~0x3f) == 0) |
| 536 | { |
| 537 | // test for small case first - assuming this is usual case. |
| 538 | // this is stored in 2 bytes. |
| 539 | |
| 540 | return((int_value << 8) | InputStreamUtil.readUnsignedByte(in)); |
| 541 | } |
| 542 | else if ((int_value & 0x80) == 0) |
| 543 | { |
| 544 | // value is stored in 4 bytes. only use low 6 bits from 1st byte. |
| 545 | |
| 546 | return( |
| 547 | ((int_value & 0x3f) << 24) | |
| 548 | (InputStreamUtil.readUnsignedByte(in) << 16) | |
| 549 | (InputStreamUtil.readUnsignedByte(in) << 8) | |
| 550 | (InputStreamUtil.readUnsignedByte(in) )); |
| 551 | |
| 552 | } |
| 553 | else |
| 554 | { |
| 555 | // value is stored in 8 bytes. only use low 7 bits from 1st byte. |
| 556 | long value = int_value; |
| 557 | |
| 558 | return( |
| 559 | (((long) (value & 0x7f) ) << 56) | |
| 560 | (((long) InputStreamUtil.readUnsignedByte(in)) << 48) | |
| 561 | (((long) InputStreamUtil.readUnsignedByte(in)) << 40) | |
| 562 | (((long) InputStreamUtil.readUnsignedByte(in)) << 32) | |
| 563 | (((long) InputStreamUtil.readUnsignedByte(in)) << 24) | |
| 564 | (((long) InputStreamUtil.readUnsignedByte(in)) << 16) | |
| 565 | (((long) InputStreamUtil.readUnsignedByte(in)) << 8) | |
| 566 | (((long) InputStreamUtil.readUnsignedByte(in)) )); |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | public static final long readLong( |
| 571 | byte[] data, |
| 572 | int offset) |
| 573 | { |
| 574 | int int_value = data[offset++]; |
| 575 | |
| 576 | if ((int_value & ~0x3f) == 0) |
| 577 | { |
| 578 | // test for small case first - assuming this is usual case. |
| 579 | // this is stored in 2 bytes. |
| 580 | |
| 581 | return((int_value << 8) | (data[offset] & 0xff)); |
| 582 | } |
| 583 | else if ((int_value & 0x80) == 0) |
| 584 | { |
| 585 | // value is stored in 4 bytes. only use low 6 bits from 1st byte. |
| 586 | |
| 587 | return( |
| 588 | ((int_value & 0x3f) << 24) | |
| 589 | ((data[offset++] & 0xff) << 16) | |
| 590 | ((data[offset++] & 0xff) << 8) | |
| 591 | ((data[offset] & 0xff) )); |
| 592 | |
| 593 | } |
| 594 | else |
| 595 | { |
| 596 | // value is stored in 8 bytes. only use low 6 bits from 1st byte. |
| 597 | return( |
| 598 | (((long) (int_value & 0x7f)) << 56) | |
| 599 | (((long) (data[offset++] & 0xff)) << 48) | |
| 600 | (((long) (data[offset++] & 0xff)) << 40) | |
| 601 | (((long) (data[offset++] & 0xff)) << 32) | |
| 602 | (((long) (data[offset++] & 0xff)) << 24) | |
| 603 | (((long) (data[offset++] & 0xff)) << 16) | |
| 604 | (((long) (data[offset++] & 0xff)) << 8) | |
| 605 | (((long) (data[offset] & 0xff)) )); |
| 606 | |
| 607 | } |
| 608 | } |
| 609 | |
| 610 | /** |
| 611 | Skip a long previously written by writeLong(). |
| 612 | |
| 613 | @exception IOException an exception was thrown by a method on in. |
| 614 | */ |
| 615 | public static final int skipLong(DataInput in) throws IOException { |
| 616 | |
| 617 | long value = in.readUnsignedByte(); |
| 618 | |
| 619 | if ((value & 0x80) == 0x80) |
| 620 | { |
| 621 | in.skipBytes(7); |
| 622 | return 8; |
| 623 | } |
| 624 | |
| 625 | |
| 626 | if ((value & 0x40) == 0x40) |
| 627 | { |
| 628 | in.skipBytes(3); |
| 629 | return 4; |
| 630 | |
| 631 | } |
| 632 | |
| 633 | in.skipBytes(1); |
| 634 | return 2; |
| 635 | } |
| 636 | |
| 637 | /** |
| 638 | Skip a long previously written by writeLong(). |
| 639 | |
| 640 | @exception IOException an exception was thrown by a method on in. |
| 641 | */ |
| 642 | public static final int skipLong(InputStream in) throws IOException { |
| 643 | |
| 644 | int value = InputStreamUtil.readUnsignedByte(in); |
| 645 | |
| 646 | int skipBytes; |
| 647 | |
| 648 | if ((value & 0x80) == 0x80) { |
| 649 | skipBytes = 7; |
| 650 | } |
| 651 | else if ((value & 0x40) == 0x40) { |
| 652 | skipBytes = 3; |
| 653 | } |
| 654 | else |
| 655 | skipBytes = 1; |
| 656 | |
| 657 | if (in.skip(skipBytes) != skipBytes) |
| 658 | throw new EOFException(); |
| 659 | |
| 660 | return skipBytes + 1; |
| 661 | } |
| 662 | |
| 663 | public static final int sizeLong(long value) { |
| 664 | |
| 665 | if (value <= 0x3fff) { |
| 666 | |
| 667 | return 2; |
| 668 | } |
| 669 | |
| 670 | if (value <= 0x3fffffff) { |
| 671 | return 4; |
| 672 | } |
| 673 | |
| 674 | return 8; |
| 675 | } |
| 676 | |
| 677 | // /* FOR TESTING |
| 678 | // ***************************************************** |
| 679 | |
| 680 | private static byte[] holder = new byte[8]; |
| 681 | private static ArrayOutputStream aos = new ArrayOutputStream(holder); |
| 682 | private static DataOutput out = new DataOutputStream(aos); |
| 683 | |
| 684 | private static ArrayInputStream ais = new ArrayInputStream(holder); |
| 685 | private static DataInput in = new DataInputStream(ais); |
| 686 | private static InputStream in_stream = ais; |
| 687 | |
| 688 | |
| 689 | private static short checkInt(int i, short oldLength) throws IOException { |
| 690 | |
| 691 | aos.setPosition(0); |
| 692 | int length = CompressedNumber.writeInt(out, i); |
| 693 | if (length != oldLength) { |
| 694 | System.out.println("changing length to " + length + " at value " + i + " 0x" + Integer.toHexString(i)); |
| 695 | |
| 696 | oldLength = (short) length; |
| 697 | } |
| 698 | |
| 699 | int writtenBytes = aos.getPosition(); |
| 700 | if (writtenBytes != length) { |
| 701 | System.out.println("MISMATCH written bytes expected " + length + " got " + writtenBytes); |
| 702 | System.exit(1); |
| 703 | } |
| 704 | |
| 705 | if (length != CompressedNumber.sizeInt(i)) { |
| 706 | System.out.println("MISMATCH sizeInt() bytes expected " + length + " got " + CompressedNumber.sizeInt(i)); |
| 707 | System.exit(1); |
| 708 | } |
| 709 | |
| 710 | ais.setPosition(0); |
| 711 | int value = CompressedNumber.readInt(in); |
| 712 | if (value != i) { |
| 713 | System.out.println("MISMATCH value readInt(DataInput) expected " + i + " got " + value); |
| 714 | System.exit(1); |
| 715 | } |
| 716 | |
| 717 | ais.setPosition(0); |
| 718 | value = ais.readCompressedInt(); |
| 719 | if (value != i) { |
| 720 | System.out.println("MISMATCH value readInt(DataInput) expected " + i + " got " + value); |
| 721 | System.exit(1); |
| 722 | } |
| 723 | |
| 724 | ais.setPosition(0); |
| 725 | value = CompressedNumber.readInt(in_stream); |
| 726 | if (value != i) { |
| 727 | System.out.println("MISMATCH value in readInt(InputStream) expected " + i + " got " + value); |
| 728 | System.exit(1); |
| 729 | } |
| 730 | |
| 731 | |
| 732 | value = CompressedNumber.readInt(holder, 0); |
| 733 | if (value != i) { |
| 734 | System.out.println( |
| 735 | "MISMATCH frome readInt(byte[], offset) value expected " + |
| 736 | i + " got " + value); |
| 737 | System.exit(1); |
| 738 | } |
| 739 | |
| 740 | ais.setPosition(0); |
| 741 | int skipLength = CompressedNumber.skipInt(in); |
| 742 | if (skipLength != length) { |
| 743 | System.out.println("MISMATCH skip length expected " + length + " got " + skipLength); |
| 744 | System.exit(1); |
| 745 | } |
| 746 | |
| 747 | int value_plus_int_length = readIntAndReturnIntPlusOverhead(holder, 0); |
| 748 | if (value_plus_int_length != (length + i + 1)) { |
| 749 | System.out.println("MISMATCH readIntAndReturnIntPlusOverhead() return expected " + (length + i) + " got " + value_plus_int_length); |
| 750 | System.exit(1); |
| 751 | } |
| 752 | |
| 753 | int skipPosition = ais.getPosition(); |
| 754 | if (skipPosition != length) { |
| 755 | System.out.println("MISMATCH skip position expected " + length + " got " + skipPosition); |
| 756 | System.exit(1); |
| 757 | } |
| 758 | |
| 759 | return oldLength; |
| 760 | } |
| 761 | |
| 762 | private static short checkLong(long i, short oldLength) throws IOException { |
| 763 | |
| 764 | aos.setPosition(0); |
| 765 | int length = CompressedNumber.writeLong(out, i); |
| 766 | if (length != oldLength) { |
| 767 | System.out.println("changing length to " + length + " at value " + i + " 0x" + Long.toHexString(i)); |
| 768 | oldLength = (short) length; |
| 769 | } |
| 770 | |
| 771 | int writtenBytes = aos.getPosition(); |
| 772 | if (writtenBytes != length) { |
| 773 | System.out.println("MISMATCH written bytes expected " + length + " got " + writtenBytes); |
| 774 | System.exit(1); |
| 775 | } |
| 776 | |
| 777 | if (length != CompressedNumber.sizeLong(i)) { |
| 778 | System.out.println("MISMATCH sizeLong() bytes expected " + length + " got " + CompressedNumber.sizeLong(i)); |
| 779 | System.exit(1); |
| 780 | } |
| 781 | |
| 782 | long value = CompressedNumber.readLong(holder, 0); |
| 783 | if (value != i) { |
| 784 | for (int j = 0; j < 8; j++) { |
| 785 | |
| 786 | System.out.println(Integer.toHexString((int) holder[j])); |
| 787 | } |
| 788 | |
| 789 | System.out.println( |
| 790 | "MISMATCH in readLong(byte[], offset) value expected " + |
| 791 | Long.toHexString(i) + " got " + value); |
| 792 | System.exit(1); |
| 793 | } |
| 794 | |
| 795 | ais.setPosition(0); |
| 796 | value = CompressedNumber.readLong(in_stream); |
| 797 | if (value != i) { |
| 798 | for (int j = 0; j < 8; j++) { |
| 799 | |
| 800 | System.out.println(Integer.toHexString((int) holder[j])); |
| 801 | } |
| 802 | System.out.println("MISMATCH value in readLong(InputStream) expected " + Long.toHexString(i) + " got " + value); |
| 803 | System.exit(1); |
| 804 | } |
| 805 | |
| 806 | ais.setPosition(0); |
| 807 | value = ais.readCompressedLong(); |
| 808 | if (value != i) { |
| 809 | for (int j = 0; j < 8; j++) { |
| 810 | |
| 811 | System.out.println(Integer.toHexString((int) holder[j])); |
| 812 | } |
| 813 | System.out.println("MISMATCH value in readLong(InputStream) expected " + Long.toHexString(i) + " got " + value); |
| 814 | System.exit(1); |
| 815 | } |
| 816 | |
| 817 | |
| 818 | ais.setPosition(0); |
| 819 | value = CompressedNumber.readLong(in); |
| 820 | if (value != i) { |
| 821 | for (int j = 0; j < 8; j++) { |
| 822 | |
| 823 | System.out.println(Integer.toHexString((int) holder[j])); |
| 824 | } |
| 825 | System.out.println("MISMATCH value in readLong(DataInput) expected " + Long.toHexString(i) + " got " + value); |
| 826 | System.exit(1); |
| 827 | } |
| 828 | |
| 829 | ais.setPosition(0); |
| 830 | int skipLength = CompressedNumber.skipLong(in); |
| 831 | if (skipLength != length) { |
| 832 | System.out.println("MISMATCH skip length expected " + length + " got " + skipLength); |
| 833 | System.exit(1); |
| 834 | } |
| 835 | |
| 836 | int skipPosition = ais.getPosition(); |
| 837 | if (skipPosition != length) { |
| 838 | System.out.println("MISMATCH skip position expected " + length + " got " + skipPosition); |
| 839 | System.exit(1); |
| 840 | } |
| 841 | |
| 842 | return oldLength; |
| 843 | } |
| 844 | |
| 845 | public static void main(String[] args) throws IOException { |
| 846 | |
| 847 | short oldLength = -1; |
| 848 | |
| 849 | System.out.println("** Testing Int"); |
| 850 | |
| 851 | oldLength = checkInt(0, oldLength); |
| 852 | oldLength = checkInt(1, oldLength); |
| 853 | oldLength = checkInt(2, oldLength); |
| 854 | |
| 855 | oldLength = checkInt(0x3f - 4, oldLength); |
| 856 | oldLength = checkInt(0x3f - 3, oldLength); |
| 857 | oldLength = checkInt(0x3f - 2, oldLength); |
| 858 | oldLength = checkInt(0x3f - 1, oldLength); |
| 859 | oldLength = checkInt(0x3f , oldLength); |
| 860 | oldLength = checkInt(0x3f + 1, oldLength); |
| 861 | oldLength = checkInt(0x3f + 2, oldLength); |
| 862 | oldLength = checkInt(0x3f + 3, oldLength); |
| 863 | oldLength = checkInt(0x3f + 4, oldLength); |
| 864 | |
| 865 | oldLength = checkInt(0x3f80 - 4, oldLength); |
| 866 | oldLength = checkInt(0x3f80 - 3, oldLength); |
| 867 | oldLength = checkInt(0x3f80 - 2, oldLength); |
| 868 | oldLength = checkInt(0x3f80 - 1, oldLength); |
| 869 | oldLength = checkInt(0x3f80 , oldLength); |
| 870 | oldLength = checkInt(0x3f80 + 1, oldLength); |
| 871 | oldLength = checkInt(0x3f80 + 2, oldLength); |
| 872 | oldLength = checkInt(0x3f80 + 3, oldLength); |
| 873 | oldLength = checkInt(0x3f80 + 4, oldLength); |
| 874 | |
| 875 | oldLength = checkInt(0x3fff - 4, oldLength); |
| 876 | oldLength = checkInt(0x3fff - 3, oldLength); |
| 877 | oldLength = checkInt(0x3fff - 2, oldLength); |
| 878 | oldLength = checkInt(0x3fff - 1, oldLength); |
| 879 | oldLength = checkInt(0x3fff , oldLength); |
| 880 | oldLength = checkInt(0x3fff + 1, oldLength); |
| 881 | oldLength = checkInt(0x3fff + 2, oldLength); |
| 882 | oldLength = checkInt(0x3fff + 3, oldLength); |
| 883 | oldLength = checkInt(0x3fff + 4, oldLength); |
| 884 | |
| 885 | oldLength = checkInt(Integer.MAX_VALUE - 4, oldLength); |
| 886 | oldLength = checkInt(Integer.MAX_VALUE - 3, oldLength); |
| 887 | oldLength = checkInt(Integer.MAX_VALUE - 2, oldLength); |
| 888 | oldLength = checkInt(Integer.MAX_VALUE - 1, oldLength); |
| 889 | oldLength = checkInt(Integer.MAX_VALUE , oldLength); |
| 890 | |
| 891 | oldLength = -1; |
| 892 | for (int i = 0; i < 0xf0000; i++) |
| 893 | { |
| 894 | oldLength = checkInt(i, oldLength); |
| 895 | } |
| 896 | |
| 897 | // takes 30 minutes to run. |
| 898 | // |
| 899 | // for (int i = 0; i < Integer.MAX_VALUE; i++) |
| 900 | // { |
| 901 | // if (i % 0x00800000 == 0) |
| 902 | // System.out.println("checking: " + i); |
| 903 | // |
| 904 | // oldLength = checkInt(i, oldLength); |
| 905 | // } |
| 906 | |
| 907 | |
| 908 | System.out.println("** Testing Long"); |
| 909 | |
| 910 | oldLength = -1; |
| 911 | for (int i = 0; i < 0xf0000; i++) |
| 912 | { |
| 913 | oldLength = checkLong(i, oldLength); |
| 914 | } |
| 915 | |
| 916 | oldLength = -1; |
| 917 | |
| 918 | oldLength = checkLong(0, oldLength); |
| 919 | oldLength = checkLong(1, oldLength); |
| 920 | oldLength = checkLong(2, oldLength); |
| 921 | |
| 922 | oldLength = checkLong(0x3fff - 2, oldLength); |
| 923 | oldLength = checkLong(0x3fff - 1, oldLength); |
| 924 | oldLength = checkLong(0x3fff , oldLength); |
| 925 | oldLength = checkLong(0x3fff + 1, oldLength); |
| 926 | oldLength = checkLong(0x3fff + 2, oldLength); |
| 927 | |
| 928 | oldLength = checkLong(0x3fffffff - 4, oldLength); |
| 929 | oldLength = checkLong(0x3fffffff - 3, oldLength); |
| 930 | oldLength = checkLong(0x3fffffff - 2, oldLength); |
| 931 | oldLength = checkLong(0x3fffffff - 1, oldLength); |
| 932 | oldLength = checkLong(0x3fffffff , oldLength); |
| 933 | oldLength = checkLong(0x3fffffff + 1, oldLength); |
| 934 | oldLength = checkLong(0x3fffffff + 2, oldLength); |
| 935 | oldLength = checkLong(0x3fffffff + 3, oldLength); |
| 936 | oldLength = checkLong(0x3fffffff + 4, oldLength); |
| 937 | |
| 938 | oldLength = checkLong(0x70000000 - 2, oldLength); |
| 939 | oldLength = checkLong(0x70000000 - 1, oldLength); |
| 940 | oldLength = checkLong(0x70000000 , oldLength); |
| 941 | oldLength = checkLong(0x70000000 + 1, oldLength); |
| 942 | oldLength = checkLong(0x70000000 + 2, oldLength); |
| 943 | |
| 944 | |
| 945 | oldLength = checkLong(Long.MAX_VALUE - 2, oldLength); |
| 946 | oldLength = checkLong(Long.MAX_VALUE - 1, oldLength); |
| 947 | oldLength = checkLong(Long.MAX_VALUE , oldLength); |
| 948 | |
| 949 | |
| 950 | } |
| 951 | // ********************************************************/ |
| 952 | } |