mail-index-util.c revision 765b5eec222d2546247e74cb9bcabd43633d2e4a
/* Copyright (c) 2003-2016 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "array.h"
#include "bsearch-insert-pos.h"
#include "mail-index-private.h"
#if WORDS_BIGENDIAN
/* FIXME: Unfortunately these functions were originally written to use
endian-specific code and we can't avoid that without breaking backwards
compatibility. When we do break it, just select one of these. */
uint32_t mail_index_uint32_to_offset(uint32_t offset)
{
i_assert(offset < 0x40000000);
i_assert((offset & 3) == 0);
offset >>= 2;
return 0x00000080 | ((offset & 0x0000007f)) |
0x00008000 | ((offset & 0x00003f80) >> 7 << 8) |
0x00800000 | ((offset & 0x001fc000) >> 14 << 16) |
0x80000000 | ((offset & 0x0fe00000) >> 21 << 24);
}
uint32_t mail_index_offset_to_uint32(uint32_t offset)
{
if ((offset & 0x80808080) != 0x80808080)
return 0;
return (((offset & 0x0000007f)) |
((offset & 0x00007f00) >> 8 << 7) |
((offset & 0x007f0000) >> 16 << 14) |
((offset & 0x7f000000) >> 24 << 21)) << 2;
}
#else
uint32_t mail_index_uint32_to_offset(uint32_t offset)
{
i_assert(offset < 0x40000000);
i_assert((offset & 3) == 0);
offset >>= 2;
return 0x80000000 | ((offset & 0x0000007f) << 24) |
0x00800000 | ((offset & 0x00003f80) >> 7 << 16) |
0x00008000 | ((offset & 0x001fc000) >> 14 << 8) |
0x00000080 | ((offset & 0x0fe00000) >> 21);
}
uint32_t mail_index_offset_to_uint32(uint32_t offset)
{
if ((offset & 0x80808080) != 0x80808080)
return 0;
return (((offset & 0x0000007f) << 21) |
((offset & 0x00007f00) >> 8 << 14) |
((offset & 0x007f0000) >> 16 << 7) |
((offset & 0x7f000000) >> 24)) << 2;
}
#endif
void mail_index_pack_num(uint8_t **p, uint32_t num)
{
/* number continues as long as the highest bit is set */
while (num >= 0x80) {
**p = (num & 0x7f) | 0x80;
*p += 1;
num >>= 7;
}
**p = num;
*p += 1;
}
int mail_index_unpack_num(const uint8_t **p, const uint8_t *end,
uint32_t *num_r)
{
const uint8_t *c = *p;
uint32_t value = 0;
unsigned int bits = 0;
for (;;) {
if (unlikely(c == end)) {
/* we should never see EOF */
*num_r = 0;
return -1;
}
value |= (*c & 0x7f) << bits;
if (*c < 0x80)
break;
bits += 7;
c++;
}
if (unlikely(bits >= 32)) {
/* broken input */
*p = end;
*num_r = 0;
return -1;
}
*p = c + 1;
*num_r = value;
return 0;
}
static int mail_index_seq_record_cmp(const uint32_t *key_seq,
const uint32_t *data_seq)
{
return (int)*key_seq - (int)*data_seq;
}
bool mail_index_seq_array_lookup(const ARRAY_TYPE(seq_array) *array,
uint32_t seq, unsigned int *idx_r)
{
return array_bsearch_insert_pos(array, &seq,
mail_index_seq_record_cmp, idx_r);
}
void mail_index_seq_array_alloc(ARRAY_TYPE(seq_array) *array,
size_t record_size)
{
size_t aligned_record_size = (record_size + 3) & ~3;
i_assert(!array_is_created(array));
array_create(array, default_pool,
sizeof(uint32_t) + aligned_record_size,
1024 / (sizeof(uint32_t) + aligned_record_size));
}
bool mail_index_seq_array_add(ARRAY_TYPE(seq_array) *array, uint32_t seq,
const void *record, size_t record_size,
void *old_record)
{
void *p;
unsigned int idx, aligned_record_size;
/* records need to be 32bit aligned */
aligned_record_size = (record_size + 3) & ~3;
if (!array_is_created(array))
mail_index_seq_array_alloc(array, record_size);
i_assert(array->arr.element_size == sizeof(seq) + aligned_record_size);
if (mail_index_seq_array_lookup(array, seq, &idx)) {
/* already there, update */
p = array_idx_modifiable(array, idx);
if (old_record != NULL) {
/* save the old record before overwriting it */
memcpy(old_record, PTR_OFFSET(p, sizeof(seq)),
record_size);
}
memcpy(PTR_OFFSET(p, sizeof(seq)), record, record_size);
return TRUE;
} else {
/* insert */
p = array_insert_space(array, idx);
memcpy(p, &seq, sizeof(seq));
memcpy(PTR_OFFSET(p, sizeof(seq)), record, record_size);
return FALSE;
}
}