--- /dev/null
+#include <assert.h>
+#include <ctype.h>
+#include <sys/stat.h>
+#include "bam_endian.h"
+#include "kstring.h"
+#include "bcf.h"
+#ifdef _USE_KNETFILE
+#include "knetfile.h"
+#endif
+
+#define TAD_LIDX_SHIFT 13
+
+typedef struct {
+ int32_t n, m;
+ uint64_t *offset;
+} bcf_lidx_t;
+
+struct __bcf_idx_t {
+ int32_t n;
+ bcf_lidx_t *index2;
+};
+
+/************
+ * indexing *
+ ************/
+
+static inline void insert_offset2(bcf_lidx_t *index2, int _beg, int _end, uint64_t offset)
+{
+ int i, beg, end;
+ beg = _beg >> TAD_LIDX_SHIFT;
+ end = (_end - 1) >> TAD_LIDX_SHIFT;
+ if (index2->m < end + 1) {
+ int old_m = index2->m;
+ index2->m = end + 1;
+ kroundup32(index2->m);
+ index2->offset = (uint64_t*)realloc(index2->offset, index2->m * 8);
+ memset(index2->offset + old_m, 0, 8 * (index2->m - old_m));
+ }
+ if (beg == end) {
+ if (index2->offset[beg] == 0) index2->offset[beg] = offset;
+ } else {
+ for (i = beg; i <= end; ++i)
+ if (index2->offset[i] == 0) index2->offset[i] = offset;
+ }
+ if (index2->n < end + 1) index2->n = end + 1;
+}
+
+static void fill_missing(bcf_idx_t *idx)
+{
+ int i, j;
+ for (i = 0; i < idx->n; ++i) {
+ bcf_lidx_t *idx2 = &idx->index2[i];
+ for (j = 1; j < idx2->n; ++j)
+ if (idx2->offset[j] == 0)
+ idx2->offset[j] = idx2->offset[j-1];
+ }
+}
+
+bcf_idx_t *bcf_idx_core(bcf_t *bp)
+{
+ bcf_idx_t *idx;
+ int32_t last_coor, last_tid;
+ uint64_t last_off;
+ kstring_t *str;
+ BGZF *fp = bp->fp;
+ bcf1_t *b;
+ int ret;
+
+ b = calloc(1, sizeof(bcf1_t));
+ str = calloc(1, sizeof(kstring_t));
+ idx = (bcf_idx_t*)calloc(1, sizeof(bcf_idx_t));
+ idx->n = bp->h.n_ref;
+ idx->index2 = calloc(bp->h.n_ref, sizeof(bcf_lidx_t));
+
+ last_tid = 0xffffffffu;
+ last_off = bgzf_tell(fp); last_coor = 0xffffffffu;
+ while ((ret = bcf_read(bp, b)) > 0) {
+ int end, tmp;
+ if (last_tid != b->tid) { // change of chromosomes
+ last_tid = b->tid;
+ } else if (last_coor > b->pos) {
+ fprintf(stderr, "[bcf_idx_core] the input is out of order\n");
+ free(str->s); free(str); free(idx); bcf_destroy(b);
+ return 0;
+ }
+ tmp = strlen(b->ref);
+ end = b->pos + (tmp > 0? tmp : 1);
+ insert_offset2(&idx->index2[b->tid], b->pos, end, last_off);
+ last_off = bgzf_tell(fp);
+ last_coor = b->pos;
+ }
+ fill_missing(idx);
+ free(str->s); free(str); bcf_destroy(b);
+ return idx;
+}
+
+void bcf_idx_destroy(bcf_idx_t *idx)
+{
+ int i;
+ if (idx == 0) return;
+ for (i = 0; i < idx->n; ++i) free(idx->index2[i].offset);
+ free(idx->index2);
+ free(idx);
+}
+
+/******************
+ * index file I/O *
+ ******************/
+
+void bcf_idx_save(const bcf_idx_t *idx, BGZF *fp)
+{
+ int32_t i, ti_is_be;
+ ti_is_be = bam_is_big_endian();
+ bgzf_write(fp, "BCI\4", 4);
+ if (ti_is_be) {
+ uint32_t x = idx->n;
+ bgzf_write(fp, bam_swap_endian_4p(&x), 4);
+ } else bgzf_write(fp, &idx->n, 4);
+ for (i = 0; i < idx->n; ++i) {
+ bcf_lidx_t *index2 = idx->index2 + i;
+ // write linear index (index2)
+ if (ti_is_be) {
+ int x = index2->n;
+ bgzf_write(fp, bam_swap_endian_4p(&x), 4);
+ } else bgzf_write(fp, &index2->n, 4);
+ if (ti_is_be) { // big endian
+ int x;
+ for (x = 0; (int)x < index2->n; ++x)
+ bam_swap_endian_8p(&index2->offset[x]);
+ bgzf_write(fp, index2->offset, 8 * index2->n);
+ for (x = 0; (int)x < index2->n; ++x)
+ bam_swap_endian_8p(&index2->offset[x]);
+ } else bgzf_write(fp, index2->offset, 8 * index2->n);
+ }
+}
+
+static bcf_idx_t *bcf_idx_load_core(BGZF *fp)
+{
+ int i, ti_is_be;
+ char magic[4];
+ bcf_idx_t *idx;
+ ti_is_be = bam_is_big_endian();
+ if (fp == 0) {
+ fprintf(stderr, "[%s] fail to load index.\n", __func__);
+ return 0;
+ }
+ bgzf_read(fp, magic, 4);
+ if (strncmp(magic, "BCI\4", 4)) {
+ fprintf(stderr, "[%s] wrong magic number.\n", __func__);
+ return 0;
+ }
+ idx = (bcf_idx_t*)calloc(1, sizeof(bcf_idx_t));
+ bgzf_read(fp, &idx->n, 4);
+ if (ti_is_be) bam_swap_endian_4p(&idx->n);
+ idx->index2 = (bcf_lidx_t*)calloc(idx->n, sizeof(bcf_lidx_t));
+ for (i = 0; i < idx->n; ++i) {
+ bcf_lidx_t *index2 = idx->index2 + i;
+ int j;
+ bgzf_read(fp, &index2->n, 4);
+ if (ti_is_be) bam_swap_endian_4p(&index2->n);
+ index2->m = index2->n;
+ index2->offset = (uint64_t*)calloc(index2->m, 8);
+ bgzf_read(fp, index2->offset, index2->n * 8);
+ if (ti_is_be)
+ for (j = 0; j < index2->n; ++j) bam_swap_endian_8p(&index2->offset[j]);
+ }
+ return idx;
+}
+
+bcf_idx_t *bcf_idx_load_local(const char *fnidx)
+{
+ BGZF *fp;
+ fp = bgzf_open(fnidx, "r");
+ if (fp) {
+ bcf_idx_t *idx = bcf_idx_load_core(fp);
+ bgzf_close(fp);
+ return idx;
+ } else return 0;
+}
+
+#ifdef _USE_KNETFILE
+static void download_from_remote(const char *url)
+{
+ const int buf_size = 1 * 1024 * 1024;
+ char *fn;
+ FILE *fp;
+ uint8_t *buf;
+ knetFile *fp_remote;
+ int l;
+ if (strstr(url, "ftp://") != url && strstr(url, "http://") != url) return;
+ l = strlen(url);
+ for (fn = (char*)url + l - 1; fn >= url; --fn)
+ if (*fn == '/') break;
+ ++fn; // fn now points to the file name
+ fp_remote = knet_open(url, "r");
+ if (fp_remote == 0) {
+ fprintf(stderr, "[download_from_remote] fail to open remote file.\n");
+ return;
+ }
+ if ((fp = fopen(fn, "w")) == 0) {
+ fprintf(stderr, "[download_from_remote] fail to create file in the working directory.\n");
+ knet_close(fp_remote);
+ return;
+ }
+ buf = (uint8_t*)calloc(buf_size, 1);
+ while ((l = knet_read(fp_remote, buf, buf_size)) != 0)
+ fwrite(buf, 1, l, fp);
+ free(buf);
+ fclose(fp);
+ knet_close(fp_remote);
+}
+#else
+static void download_from_remote(const char *url)
+{
+ return;
+}
+#endif
+
+static char *get_local_version(const char *fn)
+{
+ struct stat sbuf;
+ char *fnidx = (char*)calloc(strlen(fn) + 5, 1);
+ strcat(strcpy(fnidx, fn), ".bci");
+ if ((strstr(fnidx, "ftp://") == fnidx || strstr(fnidx, "http://") == fnidx)) {
+ char *p, *url;
+ int l = strlen(fnidx);
+ for (p = fnidx + l - 1; p >= fnidx; --p)
+ if (*p == '/') break;
+ url = fnidx; fnidx = strdup(p + 1);
+ if (stat(fnidx, &sbuf) == 0) {
+ free(url);
+ return fnidx;
+ }
+ fprintf(stderr, "[%s] downloading the index file...\n", __func__);
+ download_from_remote(url);
+ free(url);
+ }
+ if (stat(fnidx, &sbuf) == 0) return fnidx;
+ free(fnidx); return 0;
+}
+
+bcf_idx_t *bcf_idx_load(const char *fn)
+{
+ bcf_idx_t *idx;
+ char *fname = get_local_version(fn);
+ if (fname == 0) return 0;
+ idx = bcf_idx_load_local(fname);
+ free(fname);
+ return idx;
+}
+
+int bcf_idx_build2(const char *fn, const char *_fnidx)
+{
+ char *fnidx;
+ BGZF *fpidx;
+ bcf_t *bp;
+ bcf_idx_t *idx;
+ if ((bp = bcf_open(fn, "r")) == 0) {
+ fprintf(stderr, "[bcf_idx_build2] fail to open the BAM file.\n");
+ return -1;
+ }
+ idx = bcf_idx_core(bp);
+ bcf_close(bp);
+ if (_fnidx == 0) {
+ fnidx = (char*)calloc(strlen(fn) + 5, 1);
+ strcpy(fnidx, fn); strcat(fnidx, ".bci");
+ } else fnidx = strdup(_fnidx);
+ fpidx = bgzf_open(fnidx, "w");
+ if (fpidx == 0) {
+ fprintf(stderr, "[bcf_idx_build2] fail to create the index file.\n");
+ free(fnidx);
+ return -1;
+ }
+ bcf_idx_save(idx, fpidx);
+ bcf_idx_destroy(idx);
+ bgzf_close(fpidx);
+ free(fnidx);
+ return 0;
+}
+
+int bcf_idx_build(const char *fn)
+{
+ return bcf_idx_build2(fn, 0);
+}
+
+/********************************************
+ * parse a region in the format chr:beg-end *
+ ********************************************/
+
+int bcf_parse_region(void *str2id, const char *str, int *tid, int *begin, int *end)
+{
+ char *s, *p;
+ int i, l, k;
+ l = strlen(str);
+ p = s = (char*)malloc(l+1);
+ /* squeeze out "," */
+ for (i = k = 0; i != l; ++i)
+ if (str[i] != ',' && !isspace(str[i])) s[k++] = str[i];
+ s[k] = 0;
+ for (i = 0; i != k; ++i) if (s[i] == ':') break;
+ s[i] = 0;
+ if ((*tid = bcf_str2id(str2id, s)) < 0) {
+ free(s);
+ return -1;
+ }
+ if (i == k) { /* dump the whole sequence */
+ *begin = 0; *end = 1<<29; free(s);
+ return 0;
+ }
+ for (p = s + i + 1; i != k; ++i) if (s[i] == '-') break;
+ *begin = atoi(p);
+ if (i < k) {
+ p = s + i + 1;
+ *end = atoi(p);
+ } else *end = 1<<29;
+ if (*begin > 0) --*begin;
+ free(s);
+ if (*begin > *end) return -1;
+ return 0;
+}
+
+/*******************************
+ * retrieve a specified region *
+ *******************************/
+
+uint64_t bcf_idx_query(const bcf_idx_t *idx, int tid, int beg, int end)
+{
+ uint64_t min_off;
+ if (beg < 0) beg = 0;
+ if (end < beg) return 0xffffffffffffffffull;
+ min_off = (beg>>TAD_LIDX_SHIFT >= idx->index2[tid].n)? idx->index2[tid].offset[idx->index2[tid].n-1]
+ : idx->index2[tid].offset[beg>>TAD_LIDX_SHIFT];
+ assert(min_off);
+ return min_off;
+}
+
+int bcf_main_index(int argc, char *argv[])
+{
+ if (argc == 1) {
+ fprintf(stderr, "Usage: bcftools index <in.bcf>\n");
+ return 1;
+ }
+ bcf_idx_build(argv[1]);
+ return 0;
+}