external/ibm-public/postfix/dist/src/global/rec_streamlf.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      rec_streamlf 3
   6 /* SUMMARY
   7 /*      record interface to stream-lf files
   8 /* SYNOPSIS
   9 /*      #include <rec_streamlf.h>
  10 /*
  11 /*      int     rec_streamlf_get(stream, buf, maxlen)
  12 /*      VSTREAM *stream;
  13 /*      VSTRING *buf;
  14 /*      int     maxlen;
  15 /*
  16 /*      int     rec_streamlf_put(stream, type, data, len)
  17 /*      VSTREAM *stream;
  18 /*      int     type;
  19 /*      const char *data;
  20 /*      int     len;
  21 /* AUXILIARY FUNCTIONS
  22 /*      int     REC_STREAMLF_PUT_BUF(stream, type, buf)
  23 /*      VSTREAM *stream;
  24 /*      int     type;
  25 /*      VSTRING *buf;
  26 /* DESCRIPTION
  27 /*      This module implements record I/O on top of stream-lf files.
  28 /*
  29 /*      rec_streamlf_get() reads one record from the specified stream.
  30 /*      The result is null-terminated and may contain embedded null
  31 /*      characters.
  32 /*      The \fImaxlen\fR argument specifies an upper bound to the amount
  33 /*      of data read. The result is REC_TYPE_NORM when the record was
  34 /*      terminated by newline, REC_TYPE_CONT when no terminating newline
  35 /*      was found (the record was larger than \fImaxlen\fR characters or
  36 /*      EOF was reached), and REC_TYPE_EOF when no data could be read or
  37 /*      when an I/O error was detected.
  38 /*
  39 /*      rec_streamlf_put() writes one record to the named stream.
  40 /*      When the record type is REC_TYPE_NORM, a newline character is
  41 /*      appended to the output. The result is the record type, or
  42 /*      REC_TYPE_EOF in case of problems.
  43 /*
  44 /*      REC_STREAMLF_PUT_BUF() is a wrapper for rec_streamlf_put() that
  45 /*      makes it more convenient to output VSTRING buffers.
  46 /*      REC_STREAMLF_PUT_BUF() is an unsafe macro that evaluates some
  47 /*      arguments more than once.
  48 /* SEE ALSO
  49 /*      record(3) typed records
  50 /* LICENSE
  51 /* .ad
  52 /* .fi
  53 /*      The Secure Mailer license must be distributed with this software.
  54 /* AUTHOR(S)
  55 /*      Wietse Venema
  56 /*      IBM T.J. Watson Research
  57 /*      P.O. Box 704
  58 /*      Yorktown Heights, NY 10598, USA
  59 /*--*/
  60
  61 /* System library. */
  62
  63 #include <sys_defs.h>
  64
  65 /* Utility library. */
  66
  67 #include <vstring.h>
  68 #include <vstream.h>
  69
  70 /* Global library. */
  71
  72 #include <record.h>
  73 #include <rec_type.h>
  74 #include <rec_streamlf.h>
  75
  76 /* rec_streamlf_get - read record from stream-lf file */
  77
  78 int     rec_streamlf_get(VSTREAM *stream, VSTRING *buf, int maxlen)
  79 {
  80     int     n = maxlen;
  81     int     ch;
  82
  83     /*
  84      * If this one character ar a time code proves to be a performance
  85      * bottleneck, switch to block search (memchr()) and to block move
  86      * (memcpy()) operations.
  87      */
  88     VSTRING_RESET(buf);
  89     while (n-- > 0) {
  90         if ((ch = VSTREAM_GETC(stream)) == VSTREAM_EOF)
  91             return (VSTRING_LEN(buf) > 0 ? REC_TYPE_CONT : REC_TYPE_EOF);
  92         if (ch == '\n') {
  93             VSTRING_TERMINATE(buf);
  94             return (REC_TYPE_NORM);
  95         }
  96         VSTRING_ADDCH(buf, ch);
  97     }
  98     VSTRING_TERMINATE(buf);
  99     return (REC_TYPE_CONT);
 100 }
 101
 102 /* rec_streamlf_put - write record to stream-lf file */
 103
 104 int     rec_streamlf_put(VSTREAM *stream, int type, const char *data, int len)
 105 {
 106     if (len > 0)
 107         (void) vstream_fwrite(stream, data, len);
 108     if (type == REC_TYPE_NORM)
 109         (void) VSTREAM_PUTC('\n', stream);
 110     return (vstream_ferror(stream) ? REC_TYPE_EOF : type);
 111 }