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#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <stdio.h>
#include "bamlite.h"
/*********************
* from bam_endian.c *
*********************/
static inline int bam_is_big_endian()
{
long one= 1;
return !(*((char *)(&one)));
}
static inline uint16_t bam_swap_endian_2(uint16_t v)
{
return (uint16_t)(((v & 0x00FF00FFU) << 8) | ((v & 0xFF00FF00U) >> 8));
}
static inline void *bam_swap_endian_2p(void *x)
{
*(uint16_t*)x = bam_swap_endian_2(*(uint16_t*)x);
return x;
}
static inline uint32_t bam_swap_endian_4(uint32_t v)
{
v = ((v & 0x0000FFFFU) << 16) | (v >> 16);
return ((v & 0x00FF00FFU) << 8) | ((v & 0xFF00FF00U) >> 8);
}
static inline void *bam_swap_endian_4p(void *x)
{
*(uint32_t*)x = bam_swap_endian_4(*(uint32_t*)x);
return x;
}
static inline uint64_t bam_swap_endian_8(uint64_t v)
{
v = ((v & 0x00000000FFFFFFFFLLU) << 32) | (v >> 32);
v = ((v & 0x0000FFFF0000FFFFLLU) << 16) | ((v & 0xFFFF0000FFFF0000LLU) >> 16);
return ((v & 0x00FF00FF00FF00FFLLU) << 8) | ((v & 0xFF00FF00FF00FF00LLU) >> 8);
}
static inline void *bam_swap_endian_8p(void *x)
{
*(uint64_t*)x = bam_swap_endian_8(*(uint64_t*)x);
return x;
}
/**************
* from bam.c *
**************/
int bam_is_be;
bam_header_t *bam_header_init()
{
bam_is_be = bam_is_big_endian();
return (bam_header_t*)calloc(1, sizeof(bam_header_t));
}
void bam_header_destroy(bam_header_t *header)
{
int32_t i;
if (header == 0) return;
if (header->target_name) {
for (i = 0; i < header->n_targets; ++i)
free(header->target_name[i]);
free(header->target_name);
free(header->target_len);
}
free(header->text);
free(header);
}
bam_header_t *bam_header_read(bamFile fp)
{
bam_header_t *header;
char buf[4];
int magic_len;
int32_t i = 1, name_len;
// read "BAM1"
magic_len = bam_read(fp, buf, 4);
if (magic_len != 4 || strncmp(buf, "BAM\001", 4) != 0) {
fprintf(stderr, "[bam_header_read] invalid BAM binary header (this is not a BAM file).\n");
return 0;
}
header = bam_header_init();
// read plain text and the number of reference sequences
bam_read(fp, &header->l_text, 4);
if (bam_is_be) bam_swap_endian_4p(&header->l_text);
header->text = (char*)calloc(header->l_text + 1, 1);
bam_read(fp, header->text, header->l_text);
bam_read(fp, &header->n_targets, 4);
if (bam_is_be) bam_swap_endian_4p(&header->n_targets);
// read reference sequence names and lengths
header->target_name = (char**)calloc(header->n_targets, sizeof(char*));
header->target_len = (uint32_t*)calloc(header->n_targets, 4);
for (i = 0; i != header->n_targets; ++i) {
bam_read(fp, &name_len, 4);
if (bam_is_be) bam_swap_endian_4p(&name_len);
header->target_name[i] = (char*)calloc(name_len, 1);
bam_read(fp, header->target_name[i], name_len);
bam_read(fp, &header->target_len[i], 4);
if (bam_is_be) bam_swap_endian_4p(&header->target_len[i]);
}
return header;
}
static void swap_endian_data(const bam1_core_t *c, int data_len, uint8_t *data)
{
uint8_t *s;
uint32_t i, *cigar = (uint32_t*)(data + c->l_qname);
s = data + c->n_cigar*4 + c->l_qname + c->l_qseq + (c->l_qseq + 1)/2;
for (i = 0; i < c->n_cigar; ++i) bam_swap_endian_4p(&cigar[i]);
while (s < data + data_len) {
uint8_t type;
s += 2; // skip key
type = toupper(*s); ++s; // skip type
if (type == 'C' || type == 'A') ++s;
else if (type == 'S') { bam_swap_endian_2p(s); s += 2; }
else if (type == 'I' || type == 'F') { bam_swap_endian_4p(s); s += 4; }
else if (type == 'D') { bam_swap_endian_8p(s); s += 8; }
else if (type == 'Z' || type == 'H') { while (*s) ++s; ++s; }
}
}
int bam_read1(bamFile fp, bam1_t *b)
{
bam1_core_t *c = &b->core;
int32_t block_len, ret, i;
uint32_t x[8];
if ((ret = bam_read(fp, &block_len, 4)) != 4) {
if (ret == 0) return -1; // normal end-of-file
else return -2; // truncated
}
if (bam_read(fp, x, sizeof(bam1_core_t)) != sizeof(bam1_core_t)) return -3;
if (bam_is_be) {
bam_swap_endian_4p(&block_len);
for (i = 0; i < 8; ++i) bam_swap_endian_4p(x + i);
}
c->tid = x[0]; c->pos = x[1];
c->bin = x[2]>>16; c->qual = x[2]>>8&0xff; c->l_qname = x[2]&0xff;
c->flag = x[3]>>16; c->n_cigar = x[3]&0xffff;
c->l_qseq = x[4];
c->mtid = x[5]; c->mpos = x[6]; c->isize = x[7];
b->data_len = block_len - sizeof(bam1_core_t);
if (b->m_data < b->data_len) {
b->m_data = b->data_len;
kroundup32(b->m_data);
b->data = (uint8_t*)realloc(b->data, b->m_data);
}
if (bam_read(fp, b->data, b->data_len) != b->data_len) return -4;
b->l_aux = b->data_len - c->n_cigar * 4 - c->l_qname - c->l_qseq - (c->l_qseq+1)/2;
if (bam_is_be) swap_endian_data(c, b->data_len, b->data);
return 4 + block_len;
}