padding.c

   1 #include <string.h>
   2 #include <assert.h>
   3 #include "kstring.h"
   4 #include "bam.h"
   5
   6 static void replace_cigar(bam1_t *b, int n, uint32_t *cigar)
   7 {
   8         if (n != b->core.n_cigar) {
   9                 int o = b->core.l_qname + b->core.n_cigar * 4;
  10                 if (b->data_len + (n - b->core.n_cigar) * 4 > b->m_data) {
  11                         b->m_data = b->data_len + (n - b->core.n_cigar) * 4;
  12                         kroundup32(b->m_data);
  13                         b->data = (uint8_t*)realloc(b->data, b->m_data);
  14                 }
  15                 memmove(b->data + b->core.l_qname + n * 4, b->data + o, b->data_len - o);
  16                 memcpy(b->data + b->core.l_qname, cigar, n * 4);
  17                 b->data_len += (n - b->core.n_cigar) * 4;
  18                 b->core.n_cigar = n;
  19         } else memcpy(b->data + b->core.l_qname, cigar, n * 4);
  20 }
  21
  22 #define write_cigar(_c, _n, _m, _v) do { \
  23                 if (_n == _m) { \
  24                         _m = _m? _m<<1 : 4; \
  25                         _c = (uint32_t*)realloc(_c, _m * 4); \
  26                 } \
  27                 _c[_n++] = (_v); \
  28         } while (0)
  29
  30 static void unpad_seq(bam1_t *b, kstring_t *s)
  31 {
  32         int k, j, i;
  33         uint32_t *cigar = bam1_cigar(b);
  34         uint8_t *seq = bam1_seq(b);
  35         ks_resize(s, b->core.l_qseq);
  36         for (k = 0, s->l = 0, j = 0; k < b->core.n_cigar; ++k) {
  37                 int op, ol;
  38                 op = bam_cigar_op(cigar[k]);
  39                 ol = bam_cigar_oplen(cigar[k]);
  40                 assert(op == BAM_CMATCH || op == BAM_CDEL || op == BAM_CSOFT_CLIP);
  41                 if (op == BAM_CMATCH) {
  42                         for (i = 0; i < ol; ++i) s->s[s->l++] = bam1_seqi(seq, j);
  43                         ++j;
  44                 } else if (op == BAM_CSOFT_CLIP) {
  45                         j += ol;
  46                 } else {
  47                         for (i = 0; i < ol; ++i) s->s[s->l++] = 0;
  48                 }
  49         }
  50 }
  51
  52 int bam_pad2unpad(bamFile in, bamFile out)
  53 {
  54         bam_header_t *h;
  55         bam1_t *b;
  56         kstring_t r, q;
  57         uint32_t *cigar2 = 0;
  58         int n2 = 0, m2 = 0, *posmap = 0;
  59
  60         h = bam_header_read(in);
  61         bam_header_write(out, h);
  62         b = bam_init1();
  63         r.l = r.m = q.l = q.m = 0; r.s = q.s = 0;
  64         while (bam_read1(in, b) >= 0) {
  65                 uint32_t *cigar = bam1_cigar(b);
  66                 n2 = 0;
  67                 if (b->core.pos == 0 && b->core.tid >= 0 && strcmp(bam1_qname(b), h->target_name[b->core.tid]) == 0) {
  68                         int i, k;
  69                         unpad_seq(b, &r);
  70                         write_cigar(cigar2, n2, m2, bam_cigar_gen(b->core.l_qseq, BAM_CMATCH));
  71                         replace_cigar(b, n2, cigar2);
  72                         posmap = realloc(posmap, r.m * sizeof(int));
  73                         for (i = k = 0; i < r.l; ++i) {
  74                                 posmap[i] = k; // note that a read should NOT start at a padding
  75                                 if (r.s[i]) ++k;
  76                         }
  77                 } else {
  78                         int i, k, op;
  79                         unpad_seq(b, &q);
  80                         if (bam_cigar_op(cigar[0]) == BAM_CSOFT_CLIP) write_cigar(cigar2, n2, m2, cigar[0]);
  81                         for (i = 0, k = b->core.pos; i < q.l; ++i, ++k)
  82                                 q.s[i] = q.s[i]? (r.s[k]? BAM_CMATCH : BAM_CINS) : (r.s[k]? BAM_CDEL : BAM_CPAD);
  83                         for (i = k = 1, op = q.s[0]; i < q.l; ++i) {
  84                                 if (op != q.s[i]) {
  85                                         write_cigar(cigar2, n2, m2, bam_cigar_gen(k, op));
  86                                         op = q.s[i]; k = 1;
  87                                 } else ++k;
  88                         }
  89                         write_cigar(cigar2, n2, m2, bam_cigar_gen(k, op));
  90                         if (bam_cigar_op(cigar[b->core.n_cigar-1]) == BAM_CSOFT_CLIP) write_cigar(cigar2, n2, m2, cigar[b->core.n_cigar-1]);
  91                         for (i = 2; i < n2; ++i)
  92                                 if (bam_cigar_op(cigar2[i]) == BAM_CMATCH && bam_cigar_op(cigar2[i-1]) == BAM_CPAD && bam_cigar_op(cigar2[i-2]) == BAM_CMATCH)
  93                                         cigar2[i] += cigar2[i-2], cigar2[i-2] = cigar2[i-1] = 0;
  94                         for (i = k = 0; i < n2; ++i)
  95                                 if (cigar2[i]) cigar2[k++] = cigar2[i];
  96                         n2 = k;
  97                         replace_cigar(b, n2, cigar2);
  98                         b->core.pos = posmap[b->core.pos];
  99                 }
 100                 bam_write1(out, b);
 101         }
 102         free(r.s); free(q.s); free(posmap);
 103         bam_destroy1(b);
 104         bam_header_destroy(h);
 105         return 0;
 106 }
 107
 108 int main_pad2unpad(int argc, char *argv[])
 109 {
 110         bamFile in, out;
 111         if (argc == 1) {
 112                 fprintf(stderr, "Usage: samtools pad2unpad <in.bam>\n");
 113                 return 1;
 114         }
 115         in = strcmp(argv[1], "-")? bam_open(argv[1], "r") : bam_dopen(fileno(stdin), "r");
 116         out = bam_dopen(fileno(stdout), "w");
 117         bam_pad2unpad(in, out);
 118         bam_close(in); bam_close(out);
 119         return 0;
 120 }