com32/sysdump/zout.c

   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 "backend.h"
  12 #include "ctime.h"
  13
  14 #define ALLOC_CHUNK     65536
  15
  16 int init_data(struct 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
  36 static int do_deflate(struct 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
  58 int write_data(struct 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 */
  78 int flush_data(struct backend *be)
  79 {
  80     int rv = Z_OK;
  81
  82     while (rv != Z_STREAM_END) {
  83         rv = do_deflate(be, Z_FINISH);
  84         if (rv < 0)
  85             return -1;
  86     }
  87
  88     printf("Uploading data, %u bytes... ", be->zbytes);
  89
  90     if (be->write(be))
  91         return -1;
  92
  93     free(be->outbuf);
  94     be->outbuf = NULL;
  95     be->dbytes = be->zbytes = be->alloc = 0;
  96
  97     printf("done.\n");
  98     return 0;
  99 }