src/main/common/streambuf.c

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <string.h>
  19 #include <stdint.h>
  20
  21 #include "streambuf.h"
  22
  23 sbuf_t *sbufInit(sbuf_t *sbuf, uint8_t *ptr, uint8_t *end)
  24 {
  25     sbuf->ptr = ptr;
  26     sbuf->end = end;
  27     return sbuf;
  28 }
  29
  30 void sbufWriteU8(sbuf_t *dst, uint8_t val)
  31 {
  32     *dst->ptr++ = val;
  33 }
  34
  35 void sbufWriteU16(sbuf_t *dst, uint16_t val)
  36 {
  37     sbufWriteU8(dst, val >> 0);
  38     sbufWriteU8(dst, val >> 8);
  39 }
  40
  41 void sbufWriteU32(sbuf_t *dst, uint32_t val)
  42 {
  43     sbufWriteU8(dst, val >> 0);
  44     sbufWriteU8(dst, val >> 8);
  45     sbufWriteU8(dst, val >> 16);
  46     sbufWriteU8(dst, val >> 24);
  47 }
  48
  49 void sbufWriteU16BigEndian(sbuf_t *dst, uint16_t val)
  50 {
  51     sbufWriteU8(dst, val >> 8);
  52     sbufWriteU8(dst, (uint8_t)val);
  53 }
  54
  55 void sbufWriteU32BigEndian(sbuf_t *dst, uint32_t val)
  56 {
  57     sbufWriteU8(dst, val >> 24);
  58     sbufWriteU8(dst, val >> 16);
  59     sbufWriteU8(dst, val >> 8);
  60     sbufWriteU8(dst, (uint8_t)val);
  61 }
  62
  63
  64 void sbufFill(sbuf_t *dst, uint8_t data, int len)
  65 {
  66     memset(dst->ptr, data, len);
  67     dst->ptr += len;
  68 }
  69
  70 void sbufWriteData(sbuf_t *dst, const void *data, int len)
  71 {
  72     memcpy(dst->ptr, data, len);
  73     dst->ptr += len;
  74 }
  75
  76 void sbufWriteString(sbuf_t *dst, const char *string)
  77 {
  78     sbufWriteData(dst, string, strlen(string));
  79 }
  80
  81 void sbufWriteStringWithZeroTerminator(sbuf_t *dst, const char *string)
  82 {
  83     sbufWriteData(dst, string, strlen(string) + 1);
  84 }
  85
  86 uint8_t sbufReadU8(sbuf_t *src)
  87 {
  88     return *src->ptr++;
  89 }
  90
  91 uint16_t sbufReadU16(sbuf_t *src)
  92 {
  93     uint16_t ret;
  94     ret = sbufReadU8(src);
  95     ret |= sbufReadU8(src) << 8;
  96     return ret;
  97 }
  98
  99 uint32_t sbufReadU32(sbuf_t *src)
 100 {
 101     uint32_t ret;
 102     ret = sbufReadU8(src);
 103     ret |= sbufReadU8(src) <<  8;
 104     ret |= sbufReadU8(src) << 16;
 105     ret |= sbufReadU8(src) << 24;
 106     return ret;
 107 }
 108
 109 void sbufReadData(sbuf_t *src, void *data, int len)
 110 {
 111     memcpy(data, src->ptr, len);
 112 }
 113
 114 // reader - return bytes remaining in buffer
 115 // writer - return available space
 116 int sbufBytesRemaining(sbuf_t *buf)
 117 {
 118     return buf->end - buf->ptr;
 119 }
 120
 121 uint8_t* sbufPtr(sbuf_t *buf)
 122 {
 123     return buf->ptr;
 124 }
 125
 126 const uint8_t* sbufConstPtr(const sbuf_t *buf)
 127 {
 128     return buf->ptr;
 129 }
 130
 131 // advance buffer pointer
 132 // reader - skip data
 133 // writer - commit written data
 134 void sbufAdvance(sbuf_t *buf, int size)
 135 {
 136     buf->ptr += size;
 137 }
 138
 139 // modifies streambuf so that written data are prepared for reading
 140 void sbufSwitchToReader(sbuf_t *buf, uint8_t *base)
 141 {
 142     buf->end = buf->ptr;
 143     buf->ptr = base;
 144 }