1 /*
2 * bsplit - split big binaries (copy-less plan 9 version)
3 */
4
5 #include <u.h>
6 #include <libc.h>
7 #include <authsrv.h> /* for ANAMELEN */
8
9 enum {
10 Stdin,
11 Sectsiz = 512,
12 Bufsiz = 256*Sectsiz,
13 };
14
15 /* disk address (in bytes or sectors), also type of 2nd arg. to seek */
16 typedef uvlong Daddr;
17
18 #define BLEN(s) ((s)->wp - (s)->rp)
19 #define BALLOC(s) ((s)->lim - (s)->base)
20
21 typedef struct {
22 uchar* rp; /* first unconsumed byte */
23 uchar* wp; /* first empty byte */
24 uchar* lim; /* 1 past the end of the buffer */
25 uchar* base; /* start of the buffer */
26 } Buffer;
27
28 typedef struct {
29 /* parameters */
30 Daddr maxoutsz; /* maximum size of output file(s) */
31
32 Daddr fileout; /* bytes written to the current output file */
33 char *filenm;
34 int filesz; /* size of filenm */
35 char *prefix;
36 long filenum;
37 int outf; /* open output file */
38
39 Buffer buff;
40 } Copy;
41
42 /* global data */
43 char *argv0;
44
45 /* private data */
46 static Copy cp = { 512*1024*1024 }; /* default maximum size */
47 static int debug;
48
49 static void
bufreset(Buffer * bp)50 bufreset(Buffer *bp)
51 {
52 bp->rp = bp->wp = bp->base;
53 }
54
55 static void
bufinit(Buffer * bp,uchar * block,unsigned size)56 bufinit(Buffer *bp, uchar *block, unsigned size)
57 {
58 bp->base = block;
59 bp->lim = bp->base + size;
60 bufreset(bp);
61 }
62
63 static int
eopen(char * file,int mode)64 eopen(char *file, int mode)
65 {
66 int fd = open(file, mode);
67
68 if (fd < 0)
69 sysfatal("can't open %s: %r", file);
70 return fd;
71 }
72
73 static int
ecreate(char * file,int mode)74 ecreate(char *file, int mode)
75 {
76 int fd = create(file, mode, 0666);
77
78 if (fd < 0)
79 sysfatal("can't create %s: %r", file);
80 return fd;
81 }
82
83 static char *
filename(Copy * cp)84 filename(Copy *cp)
85 {
86 return cp->filenm;
87 }
88
89 static int
opennext(Copy * cp)90 opennext(Copy *cp)
91 {
92 if (cp->outf >= 0)
93 sysfatal("opennext called with file open");
94 snprint(cp->filenm, cp->filesz, "%s%5.5ld", cp->prefix, cp->filenum++);
95 cp->outf = ecreate(cp->filenm, OWRITE);
96 cp->fileout = 0;
97 return cp->outf;
98 }
99
100 static int
closeout(Copy * cp)101 closeout(Copy *cp)
102 {
103 if (cp->outf >= 0) {
104 if (close(cp->outf) < 0)
105 sysfatal("error writing %s: %r", filename(cp));
106 cp->outf = -1;
107 cp->fileout = 0;
108 }
109 return cp->outf;
110 }
111
112 /*
113 * process - process input file
114 */
115 static void
process(int in,char * inname)116 process(int in, char *inname)
117 {
118 int n = 1;
119 unsigned avail, tolim, wsz;
120 Buffer *bp = &cp.buff;
121
122 USED(inname);
123 do {
124 if (BLEN(bp) == 0) {
125 if (bp->lim == bp->wp)
126 bufreset(bp);
127 n = read(in, bp->wp, bp->lim - bp->wp);
128 if (n <= 0)
129 break;
130 bp->wp += n;
131 }
132 if (cp.outf < 0)
133 opennext(&cp);
134
135 /*
136 * write from buffer's current point to end or enough bytes to
137 * reach file-size limit.
138 */
139 avail = BLEN(bp);
140 tolim = cp.maxoutsz - cp.fileout;
141 wsz = (tolim < avail? tolim: avail);
142
143 /* try to write full sectors */
144 if (tolim >= avail && n > 0 && wsz >= Sectsiz)
145 wsz = (wsz / Sectsiz) * Sectsiz;
146 if (write(cp.outf, bp->rp, wsz) != wsz)
147 sysfatal("error writing %s: %r", filename(&cp));
148 bp->rp += wsz;
149
150 cp.fileout += wsz;
151 if (cp.fileout >= cp.maxoutsz)
152 closeout(&cp);
153 } while (n > 0 || BLEN(bp) != 0);
154 }
155
156 static void
usage(void)157 usage(void)
158 {
159 fprint(2, "usage: %s [-d][-p pfx][-s size] [file...]\n", argv0);
160 exits("usage");
161 }
162
163 void
main(int argc,char ** argv)164 main(int argc, char **argv)
165 {
166 int i, errflg = 0;
167 uchar block[Bufsiz];
168
169 cp.prefix = "bs.";
170 ARGBEGIN {
171 case 'd':
172 debug++;
173 break;
174 case 'p':
175 cp.prefix = EARGF(usage());
176 break;
177 case 's':
178 cp.maxoutsz = atoll(EARGF(usage()));
179 if (cp.maxoutsz < 1)
180 errflg++;
181 break;
182 default:
183 errflg++;
184 break;
185 } ARGEND
186 if (errflg || argc < 0)
187 usage();
188
189 bufinit(&cp.buff, block, sizeof block);
190 cp.outf = -1;
191 cp.filesz = strlen(cp.prefix) + 2*ANAMELEN; /* 2* is slop */
192 cp.filenm = malloc(cp.filesz + 1);
193 if (cp.filenm == nil)
194 sysfatal("no memory: %r");
195
196 if (argc == 0)
197 process(Stdin, "/fd/0");
198 else
199 for (i = 0; i < argc; i++) {
200 int in = eopen(argv[i], OREAD);
201
202 process(in, argv[i]);
203 close(in);
204 }
205 closeout(&cp);
206 exits(0);
207 }
208