ReactOS 0.4.15-dev-8219-ge8b88cf
lz_nonslide.c File Reference
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <strings.h>
#include "lz_nonslide.h"
Include dependency graph for lz_nonslide.c:

Go to the source code of this file.

Macros

#define MAX_MATCH   253
 
#define MIN_MATCH   2
 

Functions

void lz_init (lz_info *lzi, int wsize, int max_dist, int max_match, int min_match, int frame_size, get_chars_t get_chars, output_match_t output_match, output_literal_t output_literal, void *user_data)
 
void lz_release (lz_info *lzi)
 
void lz_reset (lz_info *lzi)
 
int lz_left_to_process (lz_info *lzi)
 
static void fill_blockbuf (lz_info *lzi, int maxchars)
 
static void lz_analyze_block (lz_info *lzi)
 
void lz_stop_compressing (lz_info *lzi)
 
int lz_compress (lz_info *lzi, int nchars)
 

Macro Definition Documentation

◆ MAX_MATCH

#define MAX_MATCH   253

Definition at line 39 of file lz_nonslide.c.

◆ MIN_MATCH

#define MIN_MATCH   2

Definition at line 40 of file lz_nonslide.c.

Function Documentation

◆ fill_blockbuf()

static void fill_blockbuf ( lz_info lzi,
int  maxchars 
)
static

Definition at line 148 of file lz_nonslide.c.

149{
150 int toread;
151 u_char *readhere;
152 int nread;
153
154 if (lzi->eofcount) return;
155 maxchars -= lz_left_to_process(lzi);
156 toread = lzi->block_buf_size - lzi->chars_in_buf;
157 if (toread > maxchars) toread = maxchars;
158 readhere = lzi->block_buf + lzi->chars_in_buf;
159 nread = lzi->get_chars(lzi, toread, readhere);
160 lzi->chars_in_buf += nread;
161 if (nread != toread)
162 lzi->eofcount++;
163}
UCHAR u_char
Definition: types.h:80
int lz_left_to_process(lz_info *lzi)
Definition: lz_nonslide.c:142
int chars_in_buf
Definition: lz_nonslide.h:36
u_char * block_buf
Definition: lz_nonslide.h:33
get_chars_t get_chars
Definition: lz_nonslide.h:47
short eofcount
Definition: lz_nonslide.h:43
int block_buf_size
Definition: lz_nonslide.h:35

Referenced by lz_compress().

◆ lz_analyze_block()

static void lz_analyze_block ( lz_info lzi)
static

Definition at line 165 of file lz_nonslide.c.

166{
167 int *lentab, *lenp;
168 u_char **prevtab, **prevp;
169 u_char *bbp, *bbe;
170 u_char *chartab[256];
171 u_char *cursor;
172 int prevlen;
173 int ch;
174 int maxlen;
175 long wasinc;
176 int max_dist = lzi->max_dist;
177#ifdef DEBUG_ANALYZE_BLOCK
178 static short n = 0;
179#endif
180#ifdef DEBUG_PERF
181 struct rusage innerloop;
182 struct timeval innertime, tmptime;
183 struct rusage outerloop;
184 struct timeval outertime;
185 struct rusage initialloop;
186 struct timeval initialtime;
187 struct rusage totalloop;
188 struct timeval totaltime;
189#endif
190
191#ifdef DEBUG_ANALYZE_BLOCK
192 fprintf(stderr, "Analyzing block %d, cur_loc = %06x\n", n, lzi->cur_loc);
193#endif
194 memset(chartab, 0, sizeof(chartab));
195 prevtab = prevp = lzi->prevtab;
196 lentab = lenp = lzi->lentab;
197 memset(prevtab, 0, sizeof(*prevtab) * lzi->chars_in_buf);
198 memset(lentab, 0, sizeof(*prevtab) * lzi->chars_in_buf);
199#ifdef DEBUG_PERF
200 memset(&innertime, 0, sizeof(innertime));
201 memset(&outertime, 0, sizeof(outertime));
202 getrusage(RUSAGE_SELF, &initialloop);
203 totalloop = initialloop;
204#endif
205 bbp = lzi->block_buf;
206 bbe = bbp + lzi->chars_in_buf;
207 while (bbp < bbe) {
208 if (chartab[ch = *bbp]) {
209 *prevp = chartab[ch];
210 *lenp = 1;
211 }
212 chartab[ch] = bbp;
213 bbp++;
214 prevp++;
215 lenp++;
216 }
217#ifdef DEBUG_PERF
218 initialtime = initialloop.ru_utime;
219 getrusage(RUSAGE_SELF, &initialloop);
220 timersub(&initialloop.ru_utime, &initialtime, &initialtime);
221#endif
222 wasinc = 1;
223 for (maxlen = 1; wasinc && (maxlen < lzi->max_match); maxlen++) {
224#ifdef DEBUG_PERF
225 getrusage(RUSAGE_SELF, &outerloop);
226#endif
227 bbp = bbe - maxlen - 1;
228 lenp = lentab + lzi->chars_in_buf - maxlen - 1;
229 prevp = prevtab + lzi->chars_in_buf - maxlen - 1;
230 wasinc = 0;
231 while (bbp > lzi->block_buf) {
232 if (*lenp == maxlen) {
233#ifdef DEBUG_PERF
234 getrusage(RUSAGE_SELF, &innerloop);
235#endif
236 ch = bbp[maxlen];
237 cursor = *prevp;
238 while(cursor && ((bbp - cursor) <= max_dist)) {
239 prevlen = *(cursor - lzi->block_buf + lentab);
240 if (cursor[maxlen] == ch) {
241 *prevp = cursor;
242 (*lenp)++;
243 wasinc++;
244 break;
245 }
246 if (prevlen != maxlen) break;
247 cursor = *(cursor - lzi->block_buf + prevtab);
248 }
249#ifdef DEBUG_PERF
250 tmptime = innerloop.ru_utime;
251 getrusage(RUSAGE_SELF, &innerloop);
252 timersub(&innerloop.ru_utime, &tmptime, &tmptime);
253 timeradd(&tmptime, &innertime, &innertime);
254#endif
255 }
256 bbp--;
257 prevp--;
258 lenp--;
259 }
260#ifdef DEBUG_PERF
261 tmptime = outerloop.ru_utime;
262 getrusage(RUSAGE_SELF, &outerloop);
263 timersub(&outerloop.ru_utime, &tmptime, &tmptime);
264 timeradd(&tmptime, &outertime, &outertime);
265#endif
266 // fprintf(stderr, "maxlen = %d, wasinc = %ld\n", maxlen, wasinc);
267 }
268#ifdef DEBUG_PERF
269 totaltime = totalloop.ru_utime;
270 getrusage(RUSAGE_SELF, &totalloop);
271 timersub(&totalloop.ru_utime, &totaltime, &totaltime);
272 fprintf(stderr, "Time spend in initial loop = %f\n", initialtime.tv_sec + initialtime.tv_usec/(double)1E6);
273 fprintf(stderr, "Time spend in outer loop = %f\n", outertime.tv_sec + outertime.tv_usec/(double)1E6);
274 fprintf(stderr, "Time spend in inner loop = %f\n", innertime.tv_sec + innertime.tv_usec/(double)1E6);
275 fprintf(stderr, "Time spend in all loops = %f\n", totaltime.tv_sec + totaltime.tv_usec/(double)1E6);
276#endif
277 lzi->analysis_valid = 1;
278#ifdef DEBUG_ANALYZE_BLOCK
279 fprintf(stderr, "Done analyzing block %d, cur_loc = %06x\n", n++, lzi->cur_loc);
280#endif
281}
GLdouble n
Definition: glext.h:7729
const char cursor[]
Definition: icontest.c:13
#define stderr
Definition: stdio.h:100
_Check_return_opt_ _CRTIMP int __cdecl fprintf(_Inout_ FILE *_File, _In_z_ _Printf_format_string_ const char *_Format,...)
#define memset(x, y, z)
Definition: compat.h:39
#define timeradd(tvp1, tvp2)
Definition: time.h:123
#define timersub(tvp1, tvp2)
Definition: time.h:116
int cur_loc
Definition: lz_nonslide.h:37
short analysis_valid
Definition: lz_nonslide.h:45
int max_match
Definition: lz_nonslide.h:31
int max_dist
Definition: lz_nonslide.h:40
u_char ** prevtab
Definition: lz_nonslide.h:41
int * lentab
Definition: lz_nonslide.h:42

Referenced by lz_compress().

◆ lz_compress()

int lz_compress ( lz_info lzi,
int  nchars 
)

Definition at line 289 of file lz_nonslide.c.

290{
291
292 u_char *bbp, *bbe;
293 int *lentab, *lenp;
294 u_char **prevtab, **prevp;
295 int len;
296 int holdback;
297 short trimmed;
298
299 lzi->stop = 0;
300 while ((lz_left_to_process(lzi) || !lzi->eofcount) && !lzi->stop && nchars > 0) {
301#if 1
302 if (!lzi->analysis_valid ||
303 (!lzi->eofcount &&
304 ((lzi->chars_in_buf- lzi->block_loc) < nchars))) {
305 int residual = lzi->chars_in_buf - lzi->block_loc;
306 int bytes_to_move = lzi->max_dist + residual;
307 if (bytes_to_move > lzi->chars_in_buf)
308 bytes_to_move = lzi->chars_in_buf;
309#ifdef DEBUG_ANALYZE_BLOCK
310 fprintf(stderr, "Moving %06x, chars_in_buf %06x, residual = %06x, nchars= %06x block_loc = %06x\n", bytes_to_move, lzi->chars_in_buf, residual, nchars, lzi->block_loc);
311#endif
312 memmove(lzi->block_buf, lzi->block_buf + lzi->chars_in_buf - bytes_to_move,
313 bytes_to_move);
314
315 lzi->block_loc = bytes_to_move - residual;
316 lzi->chars_in_buf = bytes_to_move;
317#ifdef DEBUG_ANALYZE_BLOCK
318 fprintf(stderr, "New chars_in_buf %06x, new block_loc = %06x, eof = %1d\n", lzi->chars_in_buf, lzi->block_loc, lzi->eofcount);
319#endif
320 fill_blockbuf(lzi, nchars);
321#ifdef DEBUG_ANALYZE_BLOCK
322 fprintf(stderr, "Really new chars_in_buf %06x, new block_loc = %06x, eof = %1d\n", lzi->chars_in_buf, lzi->block_loc, lzi->eofcount);
323#endif
324 lz_analyze_block(lzi);
325 }
326#else
327 if (!lzi->analysis_valid ||
328 (lzi->block_loc - lzi->chars_in_buf) == 0) {
329 lzi->block_loc = 0;
330 lzi->chars_in_buf = 0;
331 fill_blockbuf(lzi, nchars);
332 lz_analyze_block(lzi);
333 }
334#endif
335 prevtab = prevp = lzi->prevtab + lzi->block_loc;
336 lentab = lenp = lzi->lentab + lzi->block_loc;
337 bbp = lzi->block_buf + lzi->block_loc;
338 holdback = lzi->max_match;
339 if (lzi->eofcount) holdback = 0;
340 if (lzi->chars_in_buf < (nchars + lzi->block_loc))
341 bbe = lzi->block_buf + lzi->chars_in_buf - holdback;
342 else
343 bbe = bbp + nchars;
344 while ((bbp < bbe) && (!lzi->stop)) {
345 trimmed = 0;
346 len = *lenp;
347 if (lzi->frame_size && (len > (lzi->frame_size - lzi->cur_loc % lzi->frame_size))) {
348#ifdef DEBUG_TRIMMING
349 fprintf(stderr, "Trim for framing: %06x %d %d\n", lzi->cur_loc,len, (lzi->frame_size - lzi->cur_loc % lzi->frame_size));
350#endif
351 trimmed = 1;
352 len = (lzi->frame_size - lzi->cur_loc % lzi->frame_size);
353 }
354 if (len > nchars) {
355#ifdef DEBUG_TRIMMING
356 fprintf(stderr, "Trim for blocking: %06x %d %d\n", lzi->cur_loc,len, nchars);
357#endif
358 trimmed = 1;
359 len = nchars;
360 }
361 if (len >= lzi->min_match) {
362#ifdef LAZY
363 if ((bbp < bbe -1) && !trimmed &&
364 ((lenp[1] > (len + 1)) /* || ((lenp[1] == len) && (prevp[1] > prevp[0])) */)) {
365 len = 1;
366 /* this is the lazy eval case */
367 }
368 else
369#endif
370 if (lzi->output_match(lzi, (*prevp - lzi->block_buf) - lzi->block_loc,
371 len) < 0) {
372 // fprintf(stderr, "Match rejected: %06x %d\n", lzi->cur_loc, len);
373 len = 1; /* match rejected */
374 }
375 }
376 else
377 len = 1;
378
379 if (len < lzi->min_match) {
380 assert(len == 1);
381 lzi->output_literal(lzi, *bbp);
382 }
383 // fprintf(stderr, "len = %3d, *lenp = %3d, cur_loc = %06x, block_loc = %06x\n", len, *lenp, lzi->cur_loc, lzi->block_loc);
384 bbp += len;
385 prevp += len;
386 lenp += len;
387 lzi->cur_loc += len;
388 lzi->block_loc += len;
389 assert(nchars >= len);
390 nchars -= len;
391
392 }
393 }
394 return 0;
395}
#define assert(x)
Definition: debug.h:53
GLenum GLsizei len
Definition: glext.h:6722
static void lz_analyze_block(lz_info *lzi)
Definition: lz_nonslide.c:165
static void fill_blockbuf(lz_info *lzi, int maxchars)
Definition: lz_nonslide.c:148
#define memmove(s1, s2, n)
Definition: mkisofs.h:881
int frame_size
Definition: lz_nonslide.h:39
output_match_t output_match
Definition: lz_nonslide.h:48
int min_match
Definition: lz_nonslide.h:32
output_literal_t output_literal
Definition: lz_nonslide.h:49
short stop
Definition: lz_nonslide.h:44
int block_loc
Definition: lz_nonslide.h:38

Referenced by lzx_compress_block().

◆ lz_init()

void lz_init ( lz_info lzi,
int  wsize,
int  max_dist,
int  max_match,
int  min_match,
int  frame_size,
get_chars_t  get_chars,
output_match_t  output_match,
output_literal_t  output_literal,
void user_data 
)

Definition at line 42 of file lz_nonslide.c.

48{
49 /* the reason for the separate max_dist value is LZX can't reach the
50 first three characters in its nominal window. But using a smaller
51 window results in inefficiency when dealing with reset intervals
52 which are the length of the nominal window */
53
54 lzi->wsize = wsize;
55 if (max_match > wsize)
56 lzi->max_match = wsize;
57 else
58 lzi->max_match = max_match;
59
60 lzi->min_match = min_match;
61 if (lzi->min_match < 3) lzi->min_match = 3;
62
63 lzi->max_dist = max_dist;
64 lzi->block_buf_size = wsize + lzi->max_dist;
65 lzi->block_buf = malloc(lzi->block_buf_size);
66 lzi->block_bufe = lzi->block_buf + lzi->block_buf_size;
67 assert(lzi->block_buf != NULL);
68
69 lzi->cur_loc = 0;
70 lzi->block_loc = 0;
71 lzi->chars_in_buf = 0;
72 lzi->eofcount = 0;
73 lzi->get_chars = get_chars;
74 lzi->output_match = output_match;
75 lzi->output_literal = output_literal;
76 lzi->user_data = user_data;
77 lzi->frame_size = frame_size;
78 lzi->lentab = calloc(sizeof(int), lzi->block_buf_size);
79 lzi->prevtab = calloc(sizeof(u_char *), lzi->block_buf_size);
80 lzi->analysis_valid = 0;
81}
#define malloc
Definition: debug_ros.c:4
#define NULL
Definition: types.h:112
#define calloc
Definition: rosglue.h:14
int wsize
Definition: lz_nonslide.h:30
void * user_data
Definition: lz_nonslide.h:50
u_char * block_bufe
Definition: lz_nonslide.h:34

Referenced by lzx_init().

◆ lz_left_to_process()

int lz_left_to_process ( lz_info lzi)

Definition at line 142 of file lz_nonslide.c.

143{
144 return lzi->chars_in_buf - lzi->block_loc;
145}

Referenced by fill_blockbuf(), lz_compress(), and lzx_compress_block().

◆ lz_release()

void lz_release ( lz_info lzi)

Definition at line 83 of file lz_nonslide.c.

84{
85 free(lzi->block_buf);
86 free(lzi->lentab);
87 free(lzi->prevtab);
88}
#define free
Definition: debug_ros.c:5

Referenced by lzx_finish().

◆ lz_reset()

void lz_reset ( lz_info lzi)

Definition at line 90 of file lz_nonslide.c.

91{
92 int residual = lzi->chars_in_buf - lzi->block_loc;
93 memmove(lzi->block_buf, lzi->block_buf + lzi->block_loc, residual);
94 lzi->chars_in_buf = residual;
95 lzi->block_loc = 0;
96 lzi->analysis_valid = 0;
97}

Referenced by lzx_reset().

◆ lz_stop_compressing()

void lz_stop_compressing ( lz_info lzi)

Definition at line 283 of file lz_nonslide.c.

284{
285 lzi->stop = 1;
286 /* fprintf(stderr, "Stopping...\n");*/
287}

Referenced by check_entropy().