buffers: use ptrdiff_t to indicate offsets.

Previously we used int in some places and off_t for others.  Neither
is correct: ptrdiff_t is right for differences between pointers.
(off_t is only for offsets and sizes on the filesystem.)
This commit is contained in:
Nick Mathewson 2019-09-04 11:06:15 -04:00
parent ec724fe8c8
commit 3aba13f779

View File

@ -158,7 +158,7 @@ chunk_new_with_alloc_size(size_t alloc)
static inline chunk_t *
chunk_grow(chunk_t *chunk, size_t sz)
{
off_t offset;
ptrdiff_t offset;
const size_t memlen_orig = chunk->memlen;
const size_t orig_alloc = CHUNK_ALLOC_SIZE(memlen_orig);
const size_t new_alloc = CHUNK_ALLOC_SIZE(sz);
@ -440,7 +440,7 @@ chunk_copy(const chunk_t *in_chunk)
#endif
newch->next = NULL;
if (in_chunk->data) {
off_t offset = in_chunk->data - in_chunk->mem;
ptrdiff_t offset = in_chunk->data - in_chunk->mem;
newch->data = newch->mem + offset;
}
return newch;
@ -710,7 +710,8 @@ buf_move_all(buf_t *buf_out, buf_t *buf_in)
/** Internal structure: represents a position in a buffer. */
typedef struct buf_pos_t {
const chunk_t *chunk; /**< Which chunk are we pointing to? */
int pos;/**< Which character inside the chunk's data are we pointing to? */
ptrdiff_t pos;/**< Which character inside the chunk's data are we pointing
* to? */
size_t chunk_pos; /**< Total length of all previous chunks. */
} buf_pos_t;
@ -726,15 +727,15 @@ buf_pos_init(const buf_t *buf, buf_pos_t *out)
/** Advance <b>out</b> to the first appearance of <b>ch</b> at the current
* position of <b>out</b>, or later. Return -1 if no instances are found;
* otherwise returns the absolute position of the character. */
static off_t
static ptrdiff_t
buf_find_pos_of_char(char ch, buf_pos_t *out)
{
const chunk_t *chunk;
int pos;
ptrdiff_t pos;
tor_assert(out);
if (out->chunk) {
if (out->chunk->datalen) {
tor_assert(out->pos < (off_t)out->chunk->datalen);
tor_assert(out->pos < (ptrdiff_t)out->chunk->datalen);
} else {
tor_assert(out->pos == 0);
}
@ -762,7 +763,7 @@ buf_pos_inc(buf_pos_t *pos)
{
tor_assert(pos->pos < INT_MAX - 1);
++pos->pos;
if (pos->pos == (off_t)pos->chunk->datalen) {
if (pos->pos == (ptrdiff_t)pos->chunk->datalen) {
if (!pos->chunk->next)
return -1;
pos->chunk_pos += pos->chunk->datalen;
@ -836,11 +837,11 @@ buf_peek_startswith(const buf_t *buf, const char *cmd)
/** Return the index within <b>buf</b> at which <b>ch</b> first appears,
* or -1 if <b>ch</b> does not appear on buf. */
static off_t
static ptrdiff_t
buf_find_offset_of_char(buf_t *buf, char ch)
{
chunk_t *chunk;
off_t offset = 0;
ptrdiff_t offset = 0;
tor_assert(buf->datalen < INT_MAX);
for (chunk = buf->head; chunk; chunk = chunk->next) {
char *cp = memchr(chunk->data, ch, chunk->datalen);
@ -863,7 +864,7 @@ int
buf_get_line(buf_t *buf, char *data_out, size_t *data_len)
{
size_t sz;
off_t offset;
ptrdiff_t offset;
if (!buf->head)
return 0;