mongoose/src/iobuf.c
2022-08-01 12:53:25 +01:00

75 lines
2.3 KiB
C

#include "iobuf.h"
#include "arch.h"
#include "log.h"
// Not using memset for zeroing memory, cause it can be dropped by compiler
// See https://github.com/cesanta/mongoose/pull/1265
static void zeromem(volatile unsigned char *buf, size_t len) {
if (buf != NULL) {
while (len--) *buf++ = 0;
}
}
static size_t roundup(size_t size, size_t align) {
return align == 0 ? size : (size + align - 1) / align * align;
}
int mg_iobuf_resize(struct mg_iobuf *io, size_t new_size) {
int ok = 1;
new_size = roundup(new_size, io->align);
if (new_size == 0) {
zeromem(io->buf, io->size);
free(io->buf);
io->buf = NULL;
io->len = io->size = 0;
} else if (new_size != io->size) {
// NOTE(lsm): do not use realloc here. Use calloc/free only, to ease the
// porting to some obscure platforms like FreeRTOS
void *p = calloc(1, new_size);
if (p != NULL) {
size_t len = new_size < io->len ? new_size : io->len;
if (len > 0) memmove(p, io->buf, len);
zeromem(io->buf, io->size);
free(io->buf);
io->buf = (unsigned char *) p;
io->size = new_size;
} else {
ok = 0;
MG_ERROR(("%lld->%lld", (uint64_t) io->size, (uint64_t) new_size));
}
}
return ok;
}
int mg_iobuf_init(struct mg_iobuf *io, size_t size, size_t align) {
io->buf = NULL;
io->align = align;
io->size = io->len = 0;
return mg_iobuf_resize(io, size);
}
size_t mg_iobuf_add(struct mg_iobuf *io, size_t ofs, const void *buf,
size_t len) {
size_t new_size = roundup(io->len + len, io->align);
mg_iobuf_resize(io, new_size); // Attempt to resize
if (new_size != io->size) len = 0; // Resize failure, append nothing
if (ofs < io->len) memmove(io->buf + ofs + len, io->buf + ofs, io->len - ofs);
if (buf != NULL) memmove(io->buf + ofs, buf, len);
if (ofs > io->len) io->len += ofs - io->len;
io->len += len;
return len;
}
size_t mg_iobuf_del(struct mg_iobuf *io, size_t ofs, size_t len) {
if (ofs > io->len) ofs = io->len;
if (ofs + len > io->len) len = io->len - ofs;
if (io->buf) memmove(io->buf + ofs, io->buf + ofs + len, io->len - ofs - len);
if (io->buf) zeromem(io->buf + io->len - len, len);
io->len -= len;
return len;
}
void mg_iobuf_free(struct mg_iobuf *io) {
mg_iobuf_resize(io, 0);
}