1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.android.inputmethod.latin.makedict; 18 19import com.android.inputmethod.annotations.UsedForTesting; 20import com.android.inputmethod.latin.Constants; 21import com.android.inputmethod.latin.makedict.DictDecoder.DictionaryBufferFactory; 22import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions; 23 24import java.io.File; 25 26/** 27 * Dictionary File Format Specification. 28 */ 29public final class FormatSpec { 30 31 /* 32 * File header layout is as follows: 33 * 34 * v | 35 * e | MAGIC_NUMBER + version of the file format, 2 bytes. 36 * r | 37 * sion 38 * 39 * o | 40 * p | not used 4 bits 41 * t | has bigrams ? 1 bit, 1 = yes, 0 = no : CONTAINS_BIGRAMS_FLAG 42 * i | FRENCH_LIGATURE_PROCESSING_FLAG 43 * o | supports dynamic updates ? 1 bit, 1 = yes, 0 = no : SUPPORTS_DYNAMIC_UPDATE 44 * n | GERMAN_UMLAUT_PROCESSING_FLAG 45 * f | 46 * lags 47 * 48 * h | 49 * e | size of the file header, 4bytes 50 * a | including the size of the magic number, the option flags and the header size 51 * d | 52 * ersize 53 * 54 * | attributes list 55 * 56 * attributes list is: 57 * <key> = | string of characters at the char format described below, with the terminator used 58 * | to signal the end of the string. 59 * <value> = | string of characters at the char format described below, with the terminator used 60 * | to signal the end of the string. 61 * if the size of already read < headersize, goto key. 62 * 63 */ 64 65 /* 66 * Node array (FusionDictionary.PtNodeArray) layout is as follows: 67 * 68 * n | 69 * o | the number of PtNodes, 1 or 2 bytes. 70 * d | 1 byte = bbbbbbbb match 71 * e | case 1xxxxxxx => xxxxxxx << 8 + next byte 72 * c | otherwise => bbbbbbbb 73 * o | 74 * unt 75 * 76 * n | 77 * o | sequence of PtNodes, 78 * d | the layout of each PtNode is described below. 79 * e | 80 * s 81 * 82 * f | 83 * o | IF SUPPORTS_DYNAMIC_UPDATE (defined in the file header) 84 * r | forward link address, 3byte 85 * w | 1 byte = bbbbbbbb match 86 * a | case 1xxxxxxx => -((xxxxxxx << 16) + (next byte << 8) + next byte) 87 * r | otherwise => (xxxxxxx << 16) + (next byte << 8) + next byte 88 * d | 89 * linkaddress 90 */ 91 92 /* Node (FusionDictionary.PtNode) layout is as follows: 93 * | IF !SUPPORTS_DYNAMIC_UPDATE 94 * | addressType xx : mask with MASK_CHILDREN_ADDRESS_TYPE 95 * | 2 bits, 00 = no children : FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS 96 * f | 01 = 1 byte : FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE 97 * l | 10 = 2 bytes : FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES 98 * a | 11 = 3 bytes : FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES 99 * g | ELSE 100 * s | is moved ? 2 bits, 11 = no : FLAG_IS_NOT_MOVED 101 * | This must be the same as FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES 102 * | 01 = yes : FLAG_IS_MOVED 103 * | the new address is stored in the same place as the parent address 104 * | is deleted? 10 = yes : FLAG_IS_DELETED 105 * | has several chars ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_MULTIPLE_CHARS 106 * | has a terminal ? 1 bit, 1 = yes, 0 = no : FLAG_IS_TERMINAL 107 * | has shortcut targets ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_SHORTCUT_TARGETS 108 * | has bigrams ? 1 bit, 1 = yes, 0 = no : FLAG_HAS_BIGRAMS 109 * | is not a word ? 1 bit, 1 = yes, 0 = no : FLAG_IS_NOT_A_WORD 110 * | is blacklisted ? 1 bit, 1 = yes, 0 = no : FLAG_IS_BLACKLISTED 111 * 112 * p | 113 * a | IF SUPPORTS_DYNAMIC_UPDATE (defined in the file header) 114 * r | parent address, 3byte 115 * e | 1 byte = bbbbbbbb match 116 * n | case 1xxxxxxx => -((0xxxxxxx << 16) + (next byte << 8) + next byte) 117 * t | otherwise => (bbbbbbbb << 16) + (next byte << 8) + next byte 118 * a | This address is relative to the head of the PtNode. 119 * d | If the node doesn't have a parent, this field is set to 0. 120 * d | 121 * ress 122 * 123 * c | IF FLAG_HAS_MULTIPLE_CHARS 124 * h | char, char, char, char n * (1 or 3 bytes) : use PtNodeInfo for i/o helpers 125 * a | end 1 byte, = 0 126 * r | ELSE 127 * s | char 1 or 3 bytes 128 * | END 129 * 130 * f | 131 * r | IF FLAG_IS_TERMINAL 132 * e | frequency 1 byte 133 * q | 134 * 135 * c | IF SUPPORTS_DYNAMIC_UPDATE 136 * h | children address, 3 bytes 137 * i | 1 byte = bbbbbbbb match 138 * l | case 1xxxxxxx => -((0xxxxxxx << 16) + (next byte << 8) + next byte) 139 * d | otherwise => (bbbbbbbb<<16) + (next byte << 8) + next byte 140 * r | if this node doesn't have children, this field is set to 0. 141 * e | (see BinaryDictEncoderUtils#writeVariableSignedAddress) 142 * n | ELSIF 00 = FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS == addressType 143 * a | // nothing 144 * d | ELSIF 01 = FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE == addressType 145 * d | children address, 1 byte 146 * r | ELSIF 10 = FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES == addressType 147 * e | children address, 2 bytes 148 * s | ELSE // 11 = FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES = addressType 149 * s | children address, 3 bytes 150 * | END 151 * | This address is relative to the position of this field. 152 * 153 * | IF FLAG_IS_TERMINAL && FLAG_HAS_SHORTCUT_TARGETS 154 * | shortcut string list 155 * | IF FLAG_IS_TERMINAL && FLAG_HAS_BIGRAMS 156 * | bigrams address list 157 * 158 * Char format is: 159 * 1 byte = bbbbbbbb match 160 * case 000xxxxx: xxxxx << 16 + next byte << 8 + next byte 161 * else: if 00011111 (= 0x1F) : this is the terminator. This is a relevant choice because 162 * unicode code points range from 0 to 0x10FFFF, so any 3-byte value starting with 163 * 00011111 would be outside unicode. 164 * else: iso-latin-1 code 165 * This allows for the whole unicode range to be encoded, including chars outside of 166 * the BMP. Also everything in the iso-latin-1 charset is only 1 byte, except control 167 * characters which should never happen anyway (and still work, but take 3 bytes). 168 * 169 * bigram address list is: 170 * <flags> = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT 171 * | addressSign = 1 bit, : FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE 172 * | 1 = must take -address, 0 = must take +address 173 * | xx : mask with MASK_BIGRAM_ATTR_ADDRESS_TYPE 174 * | addressFormat = 2 bits, 00 = unused : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE 175 * | 01 = 1 byte : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE 176 * | 10 = 2 bytes : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES 177 * | 11 = 3 bytes : FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES 178 * | 4 bits : frequency : mask with FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY 179 * <address> | IF (01 == FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE == addressFormat) 180 * | read 1 byte, add top 4 bits 181 * | ELSIF (10 == FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES == addressFormat) 182 * | read 2 bytes, add top 4 bits 183 * | ELSE // 11 == FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES == addressFormat 184 * | read 3 bytes, add top 4 bits 185 * | END 186 * | if (FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE) then address = -address 187 * if (FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT) goto bigram_and_shortcut_address_list_is 188 * 189 * shortcut string list is: 190 * <byte size> = PTNODE_SHORTCUT_LIST_SIZE_SIZE bytes, big-endian: size of the list, in bytes. 191 * <flags> = | hasNext = 1 bit, 1 = yes, 0 = no : FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT 192 * | reserved = 3 bits, must be 0 193 * | 4 bits : frequency : mask with FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY 194 * <shortcut> = | string of characters at the char format described above, with the terminator 195 * | used to signal the end of the string. 196 * if (FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT goto flags 197 */ 198 199 public static final int MAGIC_NUMBER = 0x9BC13AFE; 200 static final int MINIMUM_SUPPORTED_VERSION = 2; 201 static final int MAXIMUM_SUPPORTED_VERSION = 4; 202 static final int NOT_A_VERSION_NUMBER = -1; 203 static final int FIRST_VERSION_WITH_DYNAMIC_UPDATE = 3; 204 static final int FIRST_VERSION_WITH_TERMINAL_ID = 4; 205 static final int VERSION3 = 3; 206 static final int VERSION4 = 4; 207 208 // These options need to be the same numeric values as the one in the native reading code. 209 static final int GERMAN_UMLAUT_PROCESSING_FLAG = 0x1; 210 // TODO: Make the native reading code read this variable. 211 static final int SUPPORTS_DYNAMIC_UPDATE = 0x2; 212 static final int FRENCH_LIGATURE_PROCESSING_FLAG = 0x4; 213 static final int CONTAINS_BIGRAMS_FLAG = 0x8; 214 215 // TODO: Make this value adaptative to content data, store it in the header, and 216 // use it in the reading code. 217 static final int MAX_WORD_LENGTH = Constants.DICTIONARY_MAX_WORD_LENGTH; 218 219 static final int PARENT_ADDRESS_SIZE = 3; 220 static final int FORWARD_LINK_ADDRESS_SIZE = 3; 221 222 // These flags are used only in the static dictionary. 223 static final int MASK_CHILDREN_ADDRESS_TYPE = 0xC0; 224 static final int FLAG_CHILDREN_ADDRESS_TYPE_NOADDRESS = 0x00; 225 static final int FLAG_CHILDREN_ADDRESS_TYPE_ONEBYTE = 0x40; 226 static final int FLAG_CHILDREN_ADDRESS_TYPE_TWOBYTES = 0x80; 227 static final int FLAG_CHILDREN_ADDRESS_TYPE_THREEBYTES = 0xC0; 228 229 static final int FLAG_HAS_MULTIPLE_CHARS = 0x20; 230 231 static final int FLAG_IS_TERMINAL = 0x10; 232 static final int FLAG_HAS_SHORTCUT_TARGETS = 0x08; 233 static final int FLAG_HAS_BIGRAMS = 0x04; 234 static final int FLAG_IS_NOT_A_WORD = 0x02; 235 static final int FLAG_IS_BLACKLISTED = 0x01; 236 237 // These flags are used only in the dynamic dictionary. 238 static final int MASK_MOVE_AND_DELETE_FLAG = 0xC0; 239 static final int FIXED_BIT_OF_DYNAMIC_UPDATE_MOVE = 0x40; 240 static final int FLAG_IS_MOVED = 0x00 | FIXED_BIT_OF_DYNAMIC_UPDATE_MOVE; 241 static final int FLAG_IS_NOT_MOVED = 0x80 | FIXED_BIT_OF_DYNAMIC_UPDATE_MOVE; 242 static final int FLAG_IS_DELETED = 0x80; 243 244 static final int FLAG_BIGRAM_SHORTCUT_ATTR_HAS_NEXT = 0x80; 245 static final int FLAG_BIGRAM_ATTR_OFFSET_NEGATIVE = 0x40; 246 static final int MASK_BIGRAM_ATTR_ADDRESS_TYPE = 0x30; 247 static final int FLAG_BIGRAM_ATTR_ADDRESS_TYPE_ONEBYTE = 0x10; 248 static final int FLAG_BIGRAM_ATTR_ADDRESS_TYPE_TWOBYTES = 0x20; 249 static final int FLAG_BIGRAM_ATTR_ADDRESS_TYPE_THREEBYTES = 0x30; 250 static final int FLAG_BIGRAM_SHORTCUT_ATTR_FREQUENCY = 0x0F; 251 252 static final int PTNODE_CHARACTERS_TERMINATOR = 0x1F; 253 254 static final int PTNODE_TERMINATOR_SIZE = 1; 255 static final int PTNODE_FLAGS_SIZE = 1; 256 static final int PTNODE_FREQUENCY_SIZE = 1; 257 static final int PTNODE_TERMINAL_ID_SIZE = 4; 258 static final int PTNODE_MAX_ADDRESS_SIZE = 3; 259 static final int PTNODE_ATTRIBUTE_FLAGS_SIZE = 1; 260 static final int PTNODE_ATTRIBUTE_MAX_ADDRESS_SIZE = 3; 261 static final int PTNODE_SHORTCUT_LIST_SIZE_SIZE = 2; 262 263 // These values are used only by version 4 or later. 264 static final String TRIE_FILE_EXTENSION = ".trie"; 265 static final String FREQ_FILE_EXTENSION = ".freq"; 266 // tat = Terminal Address Table 267 static final String TERMINAL_ADDRESS_TABLE_FILE_EXTENSION = ".tat"; 268 static final String BIGRAM_FILE_EXTENSION = ".bigram"; 269 static final String SHORTCUT_FILE_EXTENSION = ".shortcut"; 270 static final String LOOKUP_TABLE_FILE_SUFFIX = "_lookup"; 271 static final String CONTENT_TABLE_FILE_SUFFIX = "_index"; 272 static final int FREQUENCY_AND_FLAGS_SIZE = 2; 273 static final int TERMINAL_ADDRESS_TABLE_ADDRESS_SIZE = 3; 274 275 // With the English main dictionary as of October 2013, the size of bigram address table is 276 // is 584KB with the block size being 4. 277 // This is 91% of that of full address table. 278 static final int BIGRAM_ADDRESS_TABLE_BLOCK_SIZE = 4; 279 static final int BIGRAM_CONTENT_COUNT = 1; 280 static final int BIGRAM_FREQ_CONTENT_INDEX = 0; 281 static final String BIGRAM_FREQ_CONTENT_ID = "_freq"; 282 283 static final int SHORTCUT_CONTENT_COUNT = 1; 284 static final int SHORTCUT_CONTENT_INDEX = 0; 285 // With the English main dictionary as of October 2013, the size of shortcut address table is 286 // 29KB with the block size being 64. 287 // This is only 4.4% of that of full address table. 288 static final int SHORTCUT_ADDRESS_TABLE_BLOCK_SIZE = 64; 289 static final String SHORTCUT_CONTENT_ID = "_shortcut"; 290 291 static final int NO_CHILDREN_ADDRESS = Integer.MIN_VALUE; 292 static final int NO_PARENT_ADDRESS = 0; 293 static final int NO_FORWARD_LINK_ADDRESS = 0; 294 static final int INVALID_CHARACTER = -1; 295 296 static final int MAX_PTNODES_FOR_ONE_BYTE_PTNODE_COUNT = 0x7F; // 127 297 static final int MAX_PTNODES_IN_A_PT_NODE_ARRAY = 0x7FFF; // 32767 298 static final int MAX_BIGRAMS_IN_A_PTNODE = 10000; 299 static final int MAX_SHORTCUT_LIST_SIZE_IN_A_PTNODE = 0xFFFF; 300 301 static final int MAX_TERMINAL_FREQUENCY = 255; 302 static final int MAX_BIGRAM_FREQUENCY = 15; 303 304 public static final int SHORTCUT_WHITELIST_FREQUENCY = 15; 305 306 // This option needs to be the same numeric value as the one in binary_format.h. 307 static final int NOT_VALID_WORD = -99; 308 static final int SIGNED_CHILDREN_ADDRESS_SIZE = 3; 309 310 static final int UINT8_MAX = 0xFF; 311 static final int UINT16_MAX = 0xFFFF; 312 static final int UINT24_MAX = 0xFFFFFF; 313 static final int SINT24_MAX = 0x7FFFFF; 314 static final int MSB8 = 0x80; 315 static final int MSB24 = 0x800000; 316 317 /** 318 * Options about file format. 319 */ 320 public static final class FormatOptions { 321 public final int mVersion; 322 public final boolean mSupportsDynamicUpdate; 323 public final boolean mHasTerminalId; 324 @UsedForTesting 325 public FormatOptions(final int version) { 326 this(version, false); 327 } 328 329 @UsedForTesting 330 public FormatOptions(final int version, final boolean supportsDynamicUpdate) { 331 mVersion = version; 332 if (version < FIRST_VERSION_WITH_DYNAMIC_UPDATE && supportsDynamicUpdate) { 333 throw new RuntimeException("Dynamic updates are only supported with versions " 334 + FIRST_VERSION_WITH_DYNAMIC_UPDATE + " and ulterior."); 335 } 336 mSupportsDynamicUpdate = supportsDynamicUpdate; 337 mHasTerminalId = (version >= FIRST_VERSION_WITH_TERMINAL_ID); 338 } 339 } 340 341 /** 342 * Class representing file header. 343 */ 344 public static final class FileHeader { 345 public final int mHeaderSize; 346 public final DictionaryOptions mDictionaryOptions; 347 public final FormatOptions mFormatOptions; 348 // Note that these are corresponding definitions in native code in latinime::HeaderPolicy 349 // and latinime::HeaderReadWriteUtils. 350 public static final String SUPPORTS_DYNAMIC_UPDATE_ATTRIBUTE = "SUPPORTS_DYNAMIC_UPDATE"; 351 public static final String USES_FORGETTING_CURVE_ATTRIBUTE = "USES_FORGETTING_CURVE"; 352 public static final String ATTRIBUTE_VALUE_TRUE = "1"; 353 354 public static final String DICTIONARY_VERSION_ATTRIBUTE = "version"; 355 public static final String DICTIONARY_LOCALE_ATTRIBUTE = "locale"; 356 public static final String DICTIONARY_ID_ATTRIBUTE = "dictionary"; 357 private static final String DICTIONARY_DESCRIPTION_ATTRIBUTE = "description"; 358 public FileHeader(final int headerSize, final DictionaryOptions dictionaryOptions, 359 final FormatOptions formatOptions) { 360 mHeaderSize = headerSize; 361 mDictionaryOptions = dictionaryOptions; 362 mFormatOptions = formatOptions; 363 } 364 365 // Helper method to get the locale as a String 366 public String getLocaleString() { 367 return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_LOCALE_ATTRIBUTE); 368 } 369 370 // Helper method to get the version String 371 public String getVersion() { 372 return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_VERSION_ATTRIBUTE); 373 } 374 375 // Helper method to get the dictionary ID as a String 376 public String getId() { 377 return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_ID_ATTRIBUTE); 378 } 379 380 // Helper method to get the description 381 public String getDescription() { 382 // TODO: Right now each dictionary file comes with a description in its own language. 383 // It will display as is no matter the device's locale. It should be internationalized. 384 return mDictionaryOptions.mAttributes.get(FileHeader.DICTIONARY_DESCRIPTION_ATTRIBUTE); 385 } 386 } 387 388 /** 389 * Returns new dictionary decoder. 390 * 391 * @param dictFile the dictionary file. 392 * @param bufferType The type of buffer, as one of USE_* in DictDecoder. 393 * @return new dictionary decoder if the dictionary file exists, otherwise null. 394 */ 395 public static DictDecoder getDictDecoder(final File dictFile, final int bufferType) { 396 if (dictFile.isDirectory()) { 397 return new Ver4DictDecoder(dictFile, bufferType); 398 } else if (dictFile.isFile()) { 399 return new Ver3DictDecoder(dictFile, bufferType); 400 } 401 return null; 402 } 403 404 public static DictDecoder getDictDecoder(final File dictFile, 405 final DictionaryBufferFactory factory) { 406 if (dictFile.isDirectory()) { 407 return new Ver4DictDecoder(dictFile, factory); 408 } else if (dictFile.isFile()) { 409 return new Ver3DictDecoder(dictFile, factory); 410 } 411 return null; 412 } 413 414 public static DictDecoder getDictDecoder(final File dictFile) { 415 return getDictDecoder(dictFile, DictDecoder.USE_READONLY_BYTEBUFFER); 416 } 417 418 private FormatSpec() { 419 // This utility class is not publicly instantiable. 420 } 421} 422