1 /*
2 * Compress input and feed it to a block-oriented back end.
3 */
4
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <inttypes.h>
9 #include <stdbool.h>
10 #include <zlib.h>
11 #include "upload_backend.h"
12 #include "ctime.h"
13
14 #define ALLOC_CHUNK 65536
15
init_data(struct upload_backend * be,const char * argv[])16 int init_data(struct upload_backend *be, const char *argv[])
17 {
18 be->now = posix_time();
19 be->argv = argv;
20
21 memset(&be->zstream, 0, sizeof be->zstream);
22
23 be->zstream.next_out = NULL;
24 be->outbuf = NULL;
25 be->zstream.avail_out = be->alloc = 0;
26 be->dbytes = be->zbytes = 0;
27
28 /* Initialize a gzip data stream */
29 if (deflateInit2(&be->zstream, 9, Z_DEFLATED,
30 16+15, 9, Z_DEFAULT_STRATEGY) < 0)
31 return -1;
32
33 return 0;
34 }
35
do_deflate(struct upload_backend * be,int flush)36 static int do_deflate(struct upload_backend *be, int flush)
37 {
38 int rv;
39 char *buf;
40
41 while (1) {
42 rv = deflate(&be->zstream, flush);
43 be->zbytes = be->alloc - be->zstream.avail_out;
44 if (be->zstream.avail_out)
45 return rv; /* Not an issue of output space... */
46
47 buf = realloc(be->outbuf, be->alloc + ALLOC_CHUNK);
48 if (!buf)
49 return Z_MEM_ERROR;
50 be->outbuf = buf;
51 be->alloc += ALLOC_CHUNK;
52 be->zstream.next_out = (void *)(buf + be->zbytes);
53 be->zstream.avail_out = be->alloc - be->zbytes;
54 }
55 }
56
57
write_data(struct upload_backend * be,const void * buf,size_t len)58 int write_data(struct upload_backend *be, const void *buf, size_t len)
59 {
60 int rv = Z_OK;
61
62 be->zstream.next_in = (void *)buf;
63 be->zstream.avail_in = len;
64
65 be->dbytes += len;
66
67 while (be->zstream.avail_in) {
68 rv = do_deflate(be, Z_NO_FLUSH);
69 if (rv < 0) {
70 printf("do_deflate returned %d\n", rv);
71 return -1;
72 }
73 }
74 return 0;
75 }
76
77 /* Output the data and shut down the stream */
flush_data(struct upload_backend * be)78 int flush_data(struct upload_backend *be)
79 {
80 int rv = Z_OK;
81 int err=-1;
82
83 while (rv != Z_STREAM_END) {
84 rv = do_deflate(be, Z_FINISH);
85 if (rv < 0)
86 return -1;
87 }
88
89 // printf("Uploading data, %u bytes... ", be->zbytes);
90
91 if ((err=be->write(be)) != 0)
92 return err;
93
94 free(be->outbuf);
95 be->outbuf = NULL;
96 be->dbytes = be->zbytes = be->alloc = 0;
97
98 // printf("done.\n");
99 return 0;
100 }
101