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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
|
/*
* Copyright (C) 2008-2009 SVOX AG, Baslerstr. 30, 8048 Zuerich, Switzerland
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file picokfst.c
*
* FST knowledge loading and access
*
* Copyright (C) 2008-2009 SVOX AG, Baslerstr. 30, 8048 Zuerich, Switzerland
* All rights reserved.
*
* History:
* - 2009-04-20 -- initial version
*
*/
#include "picoos.h"
#include "picodbg.h"
#include "picoknow.h"
#include "picokfst.h"
#ifdef __cplusplus
extern "C" {
#endif
#if 0
}
#endif
#define FileHdrSize 4 /* size of FST file header */
/* ************************************************************/
/* function to create specialized kb, */
/* to be used by picorsrc only */
/* ************************************************************/
/** object : FSTKnowledgeBase
* shortcut : kfst
* derived from : picoknow_KnowledgeBase
*/
typedef struct kfst_subobj * kfst_SubObj;
typedef struct kfst_subobj{
picoos_uint8 * fstStream; /* the byte stream base address */
picoos_int32 hdrLen; /* length of file header */
picoos_int32 transductionMode; /* transduction mode to be used for FST */
picoos_int32 nrClasses; /* nr of pair/transition classes in FST; class is in [1..nrClasses] */
picoos_int32 nrStates; /* nr of states in FST; state is in [1..nrState] */
picoos_int32 termClass; /* pair class of terminator symbol pair; probably obsolete */
picoos_int32 alphaHashTabSize; /* size of pair alphabet hash table */
picoos_int32 alphaHashTabPos; /* absolute address of the start of the pair alphabet */
picoos_int32 transTabEntrySize; /* size in bytes of each transition table entry */
picoos_int32 transTabPos; /* absolute address of the start of the transition table */
picoos_int32 inEpsStateTabPos; /* absolute address of the start of the input epsilon transition table */
picoos_int32 accStateTabPos; /* absolute address of the table of accepting states */
} kfst_subobj_t;
/* ************************************************************/
/* primitives for reading from byte stream */
/* ************************************************************/
/* Converts 'nrBytes' bytes starting at position '*pos' in byte stream 'stream' into unsigned number 'num'.
'*pos' is modified to the position right after the number */
static void FixedBytesToUnsignedNum (picoos_uint8 * stream, picoos_uint8 nrBytes, picoos_uint32 * pos, picoos_uint32 * num)
{
picoos_int32 i;
(*num) = 0;
for (i = 0; i < nrBytes; i++) {
(*num) = ((*num) << 8) + (picoos_uint32)stream[*pos];
(*pos)++;
}
}
/* Converts 'nrBytes' bytes starting at position '*pos' in byte stream 'stream' into signed number 'num'.
'*pos' is modified to the position right after the number */
static void FixedBytesToSignedNum (picoos_uint8 * stream, picoos_uint8 nrBytes, picoos_uint32 * pos, picoos_int32 * num)
{
picoos_int32 i;
picoos_uint32 val;
val = 0;
for (i = 0; i < nrBytes; i++) {
val = (val << 8) + (picoos_uint32)stream[*pos];
(*pos)++;
}
if (val % 2 == 1) {
/* negative number */
(*num) = -((picoos_int32)((val - 1) / 2)) - 1;
} else {
/* positive number */
(*num) = val / 2;
}
}
/* Converts varying-sized sequence of bytes starting at position '*pos' in byte stream 'stream'
into (signed) number 'num'. '*pos' is modified to the position right after the number. */
static void BytesToNum (picoos_uint8 * stream, picoos_uint32 * pos, picoos_int32 * num)
{
picoos_uint32 val;
picoos_uint32 b;
val = 0;
b = (picoos_uint32)stream[*pos];
(*pos)++;
while (b < 128) {
val = (val << 7) + b;
b = (picoos_uint32)stream[*pos];
(*pos)++;
}
val = (val << 7) + (b - 128);
if (val % 2 == 1) {
/* negative number */
(*num) = -((picoos_int32)((val - 1) / 2)) - 1;
} else {
/* positive number */
(*num) = val / 2;
}
}
/* ************************************************************/
/* setting up FST from byte stream */
/* ************************************************************/
static pico_status_t kfstInitialize(register picoknow_KnowledgeBase this,
picoos_Common common)
{
picoos_uint32 curpos;
picoos_int32 offs;
kfst_subobj_t * kfst;
PICODBG_DEBUG(("kfstInitialize -- start\n"));
if (NULL == this || NULL == this->subObj) {
return picoos_emRaiseException(common->em, PICO_EXC_KB_MISSING, NULL,
NULL);
}
kfst = (kfst_subobj_t *) this->subObj;
/* +CT+ */
kfst->fstStream = this->base;
PICODBG_TRACE(("base: %d\n",this->base));
kfst->hdrLen = FileHdrSize;
curpos = kfst->hdrLen;
BytesToNum(kfst->fstStream,& curpos,& kfst->transductionMode);
BytesToNum(kfst->fstStream,& curpos,& kfst->nrClasses);
BytesToNum(kfst->fstStream,& curpos,& kfst->nrStates);
BytesToNum(kfst->fstStream,& curpos,& kfst->termClass);
BytesToNum(kfst->fstStream,& curpos,& kfst->alphaHashTabSize);
BytesToNum(kfst->fstStream,& curpos,& offs);
kfst->alphaHashTabPos = kfst->hdrLen + offs;
BytesToNum(kfst->fstStream,& curpos,& kfst->transTabEntrySize);
BytesToNum(kfst->fstStream,& curpos,& offs);
kfst->transTabPos = kfst->hdrLen + offs;
BytesToNum(kfst->fstStream,& curpos,& offs);
kfst->inEpsStateTabPos = kfst->hdrLen + offs;
BytesToNum(kfst->fstStream,& curpos,& offs);
kfst->accStateTabPos = kfst->hdrLen + offs;
/* -CT- */
return PICO_OK;
}
static pico_status_t kfstSubObjDeallocate(register picoknow_KnowledgeBase this,
picoos_MemoryManager mm)
{
if (NULL != this) {
picoos_deallocate(mm, (void *) &this->subObj);
}
return PICO_OK;
}
/* calculates a small number of data (e.g. addresses) from kb for fast access.
* This data is encapsulated in a picokfst_FST that can later be retrieved
* with picokfst_getFST. */
pico_status_t picokfst_specializeFSTKnowledgeBase(picoknow_KnowledgeBase this,
picoos_Common common)
{
pico_status_t status;
if (NULL == this) {
return picoos_emRaiseException(common->em, PICO_EXC_KB_MISSING, NULL, NULL);
}
if (0 < this->size) {
/* not a dummy kb */
this->subDeallocate = kfstSubObjDeallocate;
this->subObj = picoos_allocate(common->mm, sizeof(kfst_subobj_t));
if (NULL == this->subObj) {
return picoos_emRaiseException(common->em, PICO_EXC_OUT_OF_MEM, NULL, NULL);
}
status = kfstInitialize(this, common);
if (PICO_OK != status) {
picoos_deallocate(common->mm,(void **)&this->subObj);
}
}
return PICO_OK;
}
/* ************************************************************/
/* FST type and getFST function */
/* ************************************************************/
/* return kb FST for usage in PU */
picokfst_FST picokfst_getFST(picoknow_KnowledgeBase this)
{
if (NULL == this) {
return NULL;
} else {
return (picokfst_FST) this->subObj;
}
}
/* ************************************************************/
/* FST access methods */
/* ************************************************************/
/* see description in header file */
extern picoos_uint8 picokfst_kfstGetTransductionMode(picokfst_FST this)
{
kfst_SubObj fst = (kfst_SubObj) this;
if (fst != NULL) {
return fst->transductionMode;
} else {
return 0;
}
}
/* see description in header file */
extern void picokfst_kfstGetFSTSizes (picokfst_FST this, picoos_int32 *nrStates, picoos_int32 *nrClasses)
{
kfst_SubObj fst = (kfst_SubObj) this;
if (fst != NULL) {
*nrStates = fst->nrStates;
*nrClasses = fst->nrClasses;
} else {
*nrStates = 0;
*nrClasses = 0;
}
}
/* see description in header file */
extern void picokfst_kfstStartPairSearch (picokfst_FST this, picokfst_symid_t inSym,
picoos_bool * inSymFound, picoos_int32 * searchState)
{
picoos_uint32 pos;
picoos_int32 offs;
picoos_int32 h;
picoos_int32 inSymCellPos;
picoos_int32 inSymX;
picoos_int32 nextSameHashInSymOffs;
kfst_SubObj fst = (kfst_SubObj) this;
(*searchState) = -1;
(*inSymFound) = 0;
h = inSym % fst->alphaHashTabSize;
pos = fst->alphaHashTabPos + (h * 4);
FixedBytesToSignedNum(fst->fstStream,4,& pos,& offs);
if (offs > 0) {
inSymCellPos = fst->alphaHashTabPos + offs;
pos = inSymCellPos;
BytesToNum(fst->fstStream,& pos,& inSymX);
BytesToNum(fst->fstStream,& pos,& nextSameHashInSymOffs);
while ((inSymX != inSym) && (nextSameHashInSymOffs > 0)) {
inSymCellPos = inSymCellPos + nextSameHashInSymOffs;
pos = inSymCellPos;
BytesToNum(fst->fstStream,& pos,& inSymX);
BytesToNum(fst->fstStream,& pos,& nextSameHashInSymOffs);
}
if (inSymX == inSym) {
/* input symbol found; state is set to position after symbol cell */
(*searchState) = pos;
(*inSymFound) = 1;
}
}
}
/* see description in header file */
extern void picokfst_kfstGetNextPair (picokfst_FST this, picoos_int32 * searchState,
picoos_bool * pairFound,
picokfst_symid_t * outSym, picokfst_class_t * pairClass)
{
picoos_uint32 pos;
picoos_int32 val;
kfst_SubObj fst = (kfst_SubObj) this;
if ((*searchState) < 0) {
(*pairFound) = 0;
(*outSym) = PICOKFST_SYMID_ILLEG;
(*pairClass) = -1;
} else {
pos = (*searchState);
BytesToNum(fst->fstStream,& pos,& val);
*outSym = (picokfst_symid_t)val;
if ((*outSym) != PICOKFST_SYMID_ILLEG) {
BytesToNum(fst->fstStream,& pos,& val);
*pairClass = (picokfst_class_t)val;
(*pairFound) = 1;
(*searchState) = pos;
} else {
(*pairFound) = 0;
(*outSym) = PICOKFST_SYMID_ILLEG;
(*pairClass) = -1;
(*searchState) = -1;
}
}
}
/* see description in header file */
extern void picokfst_kfstGetTrans (picokfst_FST this, picokfst_state_t startState, picokfst_class_t transClass,
picokfst_state_t * endState)
{
picoos_uint32 pos;
picoos_int32 index;
picoos_uint32 endStateX;
kfst_SubObj fst = (kfst_SubObj) this;
if ((startState < 1) || (startState > fst->nrStates) || (transClass < 1) || (transClass > fst->nrClasses)) {
(*endState) = 0;
} else {
index = (startState - 1) * fst->nrClasses + transClass - 1;
pos = fst->transTabPos + (index * fst->transTabEntrySize);
FixedBytesToUnsignedNum(fst->fstStream,fst->transTabEntrySize,& pos,& endStateX);
(*endState) = endStateX;
}
}
/* see description in header file */
extern void picokfst_kfstStartInEpsTransSearch (picokfst_FST this, picokfst_state_t startState,
picoos_bool * inEpsTransFound, picoos_int32 * searchState)
{
picoos_int32 offs;
picoos_uint32 pos;
kfst_SubObj fst = (kfst_SubObj) this;
(*searchState) = -1;
(*inEpsTransFound) = 0;
if ((startState > 0) && (startState <= fst->nrStates)) {
pos = fst->inEpsStateTabPos + (startState - 1) * 4;
FixedBytesToSignedNum(fst->fstStream,4,& pos,& offs);
if (offs > 0) {
(*searchState) = fst->inEpsStateTabPos + offs;
(*inEpsTransFound) = 1;
}
}
}
/* see description in header file */
extern void picokfst_kfstGetNextInEpsTrans (picokfst_FST this, picoos_int32 * searchState,
picoos_bool * inEpsTransFound,
picokfst_symid_t * outSym, picokfst_state_t * endState)
{
picoos_uint32 pos;
picoos_int32 val;
kfst_SubObj fst = (kfst_SubObj) this;
if ((*searchState) < 0) {
(*inEpsTransFound) = 0;
(*outSym) = PICOKFST_SYMID_ILLEG;
(*endState) = 0;
} else {
pos = (*searchState);
BytesToNum(fst->fstStream,& pos,& val);
*outSym = (picokfst_symid_t)val;
if ((*outSym) != PICOKFST_SYMID_ILLEG) {
BytesToNum(fst->fstStream,& pos,& val);
*endState = (picokfst_state_t)val;
(*inEpsTransFound) = 1;
(*searchState) = pos;
} else {
(*inEpsTransFound) = 0;
(*outSym) = PICOKFST_SYMID_ILLEG;
(*endState) = 0;
(*searchState) = -1;
}
}
}
/* see description in header file */
extern picoos_bool picokfst_kfstIsAcceptingState (picokfst_FST this, picokfst_state_t state)
{
picoos_uint32 pos;
picoos_uint32 val;
kfst_SubObj fst = (kfst_SubObj) this;
if ((state > 0) && (state <= fst->nrStates)) {
pos = fst->accStateTabPos + (state - 1);
FixedBytesToUnsignedNum(fst->fstStream,1,& pos,& val);
return (val == 1);
} else {
return 0;
}
}
#ifdef __cplusplus
}
#endif
/* End picofst.c */
|