1 324891a5 2006-06-25 devnull #include <u.h>
2 324891a5 2006-06-25 devnull #include <libc.h>
3 324891a5 2006-06-25 devnull #include <draw.h>
4 324891a5 2006-06-25 devnull #include <memdraw.h>
6 8e5ae416 2009-07-29 rsc #define CHUNK 16000
8 324891a5 2006-06-25 devnull #define HSHIFT 3 /* HSHIFT==5 runs slightly faster, but hash table is 64x bigger */
9 324891a5 2006-06-25 devnull #define NHASH (1<<(HSHIFT*NMATCH))
10 324891a5 2006-06-25 devnull #define HMASK (NHASH-1)
11 324891a5 2006-06-25 devnull #define hupdate(h, c) ((((h)<<HSHIFT)^(c))&HMASK)
12 324891a5 2006-06-25 devnull typedef struct Hlist Hlist;
13 324891a5 2006-06-25 devnull struct Hlist{
14 324891a5 2006-06-25 devnull uchar *s;
15 324891a5 2006-06-25 devnull Hlist *next, *prev;
19 324891a5 2006-06-25 devnull writememimage(int fd, Memimage *i)
21 324891a5 2006-06-25 devnull uchar *outbuf, *outp, *eout; /* encoded data, pointer, end */
22 324891a5 2006-06-25 devnull uchar *loutp; /* start of encoded line */
23 324891a5 2006-06-25 devnull Hlist *hash; /* heads of hash chains of past strings */
24 324891a5 2006-06-25 devnull Hlist *chain, *hp; /* hash chain members, pointer */
25 324891a5 2006-06-25 devnull Hlist *cp; /* next Hlist to fall out of window */
26 324891a5 2006-06-25 devnull int h; /* hash value */
27 324891a5 2006-06-25 devnull uchar *line, *eline; /* input line, end pointer */
28 324891a5 2006-06-25 devnull uchar *data, *edata; /* input buffer, end pointer */
29 324891a5 2006-06-25 devnull u32int n; /* length of input buffer */
30 324891a5 2006-06-25 devnull u32int nb; /* # of bytes returned by unloadimage */
31 324891a5 2006-06-25 devnull int bpl; /* input line length */
32 324891a5 2006-06-25 devnull int offs, runlen; /* offset, length of consumed data */
33 324891a5 2006-06-25 devnull uchar dumpbuf[NDUMP]; /* dump accumulator */
34 324891a5 2006-06-25 devnull int ndump; /* length of dump accumulator */
35 324891a5 2006-06-25 devnull int miny, dy; /* y values while unloading input */
36 324891a5 2006-06-25 devnull int ncblock; /* size of compressed blocks */
37 324891a5 2006-06-25 devnull Rectangle r;
38 324891a5 2006-06-25 devnull uchar *p, *q, *s, *es, *t;
39 324891a5 2006-06-25 devnull char hdr[11+5*12+1];
40 324891a5 2006-06-25 devnull char cbuf[20];
42 324891a5 2006-06-25 devnull r = i->r;
43 324891a5 2006-06-25 devnull bpl = bytesperline(r, i->depth);
44 324891a5 2006-06-25 devnull n = Dy(r)*bpl;
45 324891a5 2006-06-25 devnull data = malloc(n);
46 324891a5 2006-06-25 devnull ncblock = _compblocksize(r, i->depth);
47 324891a5 2006-06-25 devnull outbuf = malloc(ncblock);
48 324891a5 2006-06-25 devnull hash = malloc(NHASH*sizeof(Hlist));
49 324891a5 2006-06-25 devnull chain = malloc(NMEM*sizeof(Hlist));
50 324891a5 2006-06-25 devnull if(data == 0 || outbuf == 0 || hash == 0 || chain == 0){
52 324891a5 2006-06-25 devnull free(data);
53 324891a5 2006-06-25 devnull free(outbuf);
54 324891a5 2006-06-25 devnull free(hash);
55 324891a5 2006-06-25 devnull free(chain);
56 324891a5 2006-06-25 devnull return -1;
58 324891a5 2006-06-25 devnull for(miny = r.min.y; miny != r.max.y; miny += dy){
59 324891a5 2006-06-25 devnull dy = r.max.y-miny;
60 324891a5 2006-06-25 devnull if(dy*bpl > CHUNK)
61 324891a5 2006-06-25 devnull dy = CHUNK/bpl;
62 324891a5 2006-06-25 devnull nb = unloadmemimage(i, Rect(r.min.x, miny, r.max.x, miny+dy),
63 324891a5 2006-06-25 devnull data+(miny-r.min.y)*bpl, dy*bpl);
64 324891a5 2006-06-25 devnull if(nb != dy*bpl)
65 324891a5 2006-06-25 devnull goto ErrOut;
67 324891a5 2006-06-25 devnull sprint(hdr, "compressed\n%11s %11d %11d %11d %11d ",
68 324891a5 2006-06-25 devnull chantostr(cbuf, i->chan), r.min.x, r.min.y, r.max.x, r.max.y);
69 324891a5 2006-06-25 devnull if(write(fd, hdr, 11+5*12) != 11+5*12)
70 324891a5 2006-06-25 devnull goto ErrOut;
71 324891a5 2006-06-25 devnull edata = data+n;
72 324891a5 2006-06-25 devnull eout = outbuf+ncblock;
73 324891a5 2006-06-25 devnull line = data;
74 324891a5 2006-06-25 devnull r.max.y = r.min.y;
75 324891a5 2006-06-25 devnull while(line != edata){
76 324891a5 2006-06-25 devnull memset(hash, 0, NHASH*sizeof(Hlist));
77 324891a5 2006-06-25 devnull memset(chain, 0, NMEM*sizeof(Hlist));
78 324891a5 2006-06-25 devnull cp = chain;
80 324891a5 2006-06-25 devnull outp = outbuf;
81 324891a5 2006-06-25 devnull for(n = 0; n != NMATCH; n++)
82 324891a5 2006-06-25 devnull h = hupdate(h, line[n]);
83 324891a5 2006-06-25 devnull loutp = outbuf;
84 324891a5 2006-06-25 devnull while(line != edata){
85 324891a5 2006-06-25 devnull ndump = 0;
86 324891a5 2006-06-25 devnull eline = line+bpl;
87 324891a5 2006-06-25 devnull for(p = line; p != eline; ){
88 324891a5 2006-06-25 devnull if(eline-p < NRUN)
89 324891a5 2006-06-25 devnull es = eline;
91 324891a5 2006-06-25 devnull es = p+NRUN;
93 324891a5 2006-06-25 devnull runlen = 0;
94 324891a5 2006-06-25 devnull for(hp = hash[h].next; hp; hp = hp->next){
95 324891a5 2006-06-25 devnull s = p + runlen;
96 324891a5 2006-06-25 devnull if(s >= es)
97 324891a5 2006-06-25 devnull continue;
98 324891a5 2006-06-25 devnull t = hp->s + runlen;
99 324891a5 2006-06-25 devnull for(; s >= p; s--)
100 324891a5 2006-06-25 devnull if(*s != *t--)
101 324891a5 2006-06-25 devnull goto matchloop;
102 324891a5 2006-06-25 devnull t += runlen+2;
103 324891a5 2006-06-25 devnull s += runlen+2;
104 324891a5 2006-06-25 devnull for(; s < es; s++)
105 324891a5 2006-06-25 devnull if(*s != *t++)
107 324891a5 2006-06-25 devnull n = s-p;
108 324891a5 2006-06-25 devnull if(n > runlen){
109 324891a5 2006-06-25 devnull runlen = n;
110 324891a5 2006-06-25 devnull q = hp->s;
111 324891a5 2006-06-25 devnull if(n == NRUN)
114 324891a5 2006-06-25 devnull matchloop: ;
116 324891a5 2006-06-25 devnull if(runlen < NMATCH){
117 324891a5 2006-06-25 devnull if(ndump == NDUMP){
118 324891a5 2006-06-25 devnull if(eout-outp < ndump+1)
119 324891a5 2006-06-25 devnull goto Bfull;
120 324891a5 2006-06-25 devnull *outp++ = ndump-1+128;
121 324891a5 2006-06-25 devnull memmove(outp, dumpbuf, ndump);
122 324891a5 2006-06-25 devnull outp += ndump;
123 324891a5 2006-06-25 devnull ndump = 0;
125 324891a5 2006-06-25 devnull dumpbuf[ndump++] = *p;
126 324891a5 2006-06-25 devnull runlen = 1;
129 324891a5 2006-06-25 devnull if(ndump != 0){
130 324891a5 2006-06-25 devnull if(eout-outp < ndump+1)
131 324891a5 2006-06-25 devnull goto Bfull;
132 324891a5 2006-06-25 devnull *outp++ = ndump-1+128;
133 324891a5 2006-06-25 devnull memmove(outp, dumpbuf, ndump);
134 324891a5 2006-06-25 devnull outp += ndump;
135 324891a5 2006-06-25 devnull ndump = 0;
137 324891a5 2006-06-25 devnull offs = p-q-1;
138 324891a5 2006-06-25 devnull if(eout-outp < 2)
139 324891a5 2006-06-25 devnull goto Bfull;
140 324891a5 2006-06-25 devnull *outp++ = ((runlen-NMATCH)<<2) + (offs>>8);
141 324891a5 2006-06-25 devnull *outp++ = offs&255;
143 324891a5 2006-06-25 devnull for(q = p+runlen; p != q; p++){
144 324891a5 2006-06-25 devnull if(cp->prev)
145 324891a5 2006-06-25 devnull cp->prev->next = 0;
146 324891a5 2006-06-25 devnull cp->next = hash[h].next;
147 324891a5 2006-06-25 devnull cp->prev = &hash[h];
148 324891a5 2006-06-25 devnull if(cp->next)
149 324891a5 2006-06-25 devnull cp->next->prev = cp;
150 324891a5 2006-06-25 devnull cp->prev->next = cp;
151 324891a5 2006-06-25 devnull cp->s = p;
152 324891a5 2006-06-25 devnull if(++cp == &chain[NMEM])
153 324891a5 2006-06-25 devnull cp = chain;
154 324891a5 2006-06-25 devnull if(edata-p > NMATCH)
155 324891a5 2006-06-25 devnull h = hupdate(h, p[NMATCH]);
158 324891a5 2006-06-25 devnull if(ndump != 0){
159 324891a5 2006-06-25 devnull if(eout-outp < ndump+1)
160 324891a5 2006-06-25 devnull goto Bfull;
161 324891a5 2006-06-25 devnull *outp++ = ndump-1+128;
162 324891a5 2006-06-25 devnull memmove(outp, dumpbuf, ndump);
163 324891a5 2006-06-25 devnull outp += ndump;
165 324891a5 2006-06-25 devnull line = eline;
166 324891a5 2006-06-25 devnull loutp = outp;
167 324891a5 2006-06-25 devnull r.max.y++;
170 324891a5 2006-06-25 devnull if(loutp == outbuf)
171 324891a5 2006-06-25 devnull goto ErrOut;
172 324891a5 2006-06-25 devnull n = loutp-outbuf;
173 324891a5 2006-06-25 devnull sprint(hdr, "%11d %11ld ", r.max.y, n);
174 324891a5 2006-06-25 devnull write(fd, hdr, 2*12);
175 324891a5 2006-06-25 devnull write(fd, outbuf, n);
176 324891a5 2006-06-25 devnull r.min.y = r.max.y;
178 324891a5 2006-06-25 devnull free(data);
179 324891a5 2006-06-25 devnull free(outbuf);
180 324891a5 2006-06-25 devnull free(hash);
181 324891a5 2006-06-25 devnull free(chain);
182 324891a5 2006-06-25 devnull return 0;
