Add bcf_sr_add_hreader() interface

This is like bcf_sr_add_reader but the caller supplies an existing
open htsFile instead of a filename.

Fixes #1862

Author: vasudeva8

htslib/synced_bcf_reader.h

@@ -1,7 +1,7 @@
 /// @file htslib/synced_bcf_reader.h
 /// Stream through multiple VCF files.
 /*
-    Copyright (C) 2012-2017, 2019-2024 Genome Research Ltd.
+    Copyright (C) 2012-2017, 2019-2025 Genome Research Ltd.
 
     Author: Petr Danecek <[email protected]>
 
@@ -233,10 +233,30 @@ void bcf_sr_destroy_threads(bcf_srs_t *files);
  *
  *  See also the bcf_srs_t data structure for parameters controlling
  *  the reader's logic.
+ *  Invokes bcf_sr_add_hreader with opened file
  */
 HTSLIB_EXPORT
 int bcf_sr_add_reader(bcf_srs_t *readers, const char *fname);
 
+/**
+ *  bcf_sr_add_hreader() - open new reader using htsfile
+ *  @readers: holder of the open readers
+ *  @file_ptr: htsfile already opened
+ *  @autoclose: close file along with reader or not, 1 - close, 0 - do not close
+ *  @idxname: index file name for file in @file_ptr
+ *
+ *  Returns 1 if the call succeeded, or 0 on error.
+ *
+ *  See also the bcf_srs_t data structure for parameters controlling
+ *  the reader's logic.
+ *  If idxname is NULL, uses file_ptr->fn to find index file.
+ *  With idxname as NULL, index file must be present along with the file with
+ *  default name
+ */
+HTSLIB_EXPORT
+int bcf_sr_add_hreader(bcf_srs_t *readers, htsFile *file_ptr, int autoclose,
+    const char *idxname);
+
 HTSLIB_EXPORT
 void bcf_sr_remove_reader(bcf_srs_t *files, int i);
 

synced_bcf_reader.c

@@ -1,6 +1,6 @@
 /*  synced_bcf_reader.c -- stream through multiple VCF files.
 
-    Copyright (C) 2012-2023 Genome Research Ltd.
+    Copyright (C) 2012-2023, 2025 Genome Research Ltd.
 
     Author: Petr Danecek <[email protected]>
 
@@ -69,6 +69,7 @@ typedef struct
 {
     sr_sort_t sort;
     int regions_overlap, targets_overlap;
+    int *closefile;             // close htsfile with sync reader close or not
 }
 aux_t;
 
@@ -251,13 +252,32 @@ void bcf_sr_destroy_threads(bcf_srs_t *files) {
 int bcf_sr_add_reader(bcf_srs_t *files, const char *fname)
 {
     char fmode[5];
+    int ret = 0;
+    const char *idxname = NULL;
+
     strcpy(fmode, "r");
     vcf_open_mode(fmode+1, fname, NULL);
     htsFile* file_ptr = hts_open(fname, fmode);
     if ( ! file_ptr ) {
         files->errnum = open_failed;
         return 0;
     }
+    //get idx name and pass to add_hreader
+    idxname = strstr(fname, HTS_IDX_DELIM);
+    idxname += idxname ? sizeof(HTS_IDX_DELIM) - 1 : 0;
+    if (!(ret = bcf_sr_add_hreader(files, file_ptr, 1, idxname))) {
+        hts_close(file_ptr);    //failed, close the file
+    }
+    return ret;
+}
+
+int bcf_sr_add_hreader(bcf_srs_t *files, htsFile *file_ptr, int autoclose, const char *idxname)
+{
+    aux_t *auxdata = NULL;
+    if ( ! file_ptr ) {
+        files->errnum = open_failed;
+        return 0;
+    }
 
     files->has_line = (int*) realloc(files->has_line, sizeof(int)*(files->nreaders+1));
     files->has_line[files->nreaders] = 0;
@@ -274,7 +294,7 @@ int bcf_sr_add_reader(bcf_srs_t *files, const char *fname)
         BGZF *bgzf = hts_get_bgzfp(reader->file);
         if ( bgzf && bgzf_check_EOF(bgzf) == 0 ) {
             files->errnum = no_eof;
-            hts_log_warning("No BGZF EOF marker; file '%s' may be truncated", fname);
+            hts_log_warning("No BGZF EOF marker; file '%s' may be truncated", file_ptr->fn);
         }
         if (files->p)
             bgzf_thread_pool(bgzf, files->p->pool, files->p->qsize);
@@ -290,7 +310,7 @@ int bcf_sr_add_reader(bcf_srs_t *files, const char *fname)
                 return 0;
             }
 
-            reader->tbx_idx = tbx_index_load(fname);
+            reader->tbx_idx = tbx_index_load2(file_ptr->fn, idxname);
             if ( !reader->tbx_idx )
             {
                 files->errnum = idx_load_failed;
@@ -309,7 +329,7 @@ int bcf_sr_add_reader(bcf_srs_t *files, const char *fname)
 
             reader->header = bcf_hdr_read(reader->file);
 
-            reader->bcf_idx = bcf_index_load(fname);
+            reader->bcf_idx = bcf_index_load2(file_ptr->fn, idxname);
             if ( !reader->bcf_idx )
             {
                 files->errnum = idx_load_failed;
@@ -362,7 +382,7 @@ int bcf_sr_add_reader(bcf_srs_t *files, const char *fname)
         return 0;
     }
 
-    reader->fname = strdup(fname);
+    reader->fname = strdup(file_ptr->fn);
     if ( files->apply_filters )
         reader->filter_ids = init_filters(reader->header, files->apply_filters, &reader->nfilter_ids);
 
@@ -413,6 +433,18 @@ int bcf_sr_add_reader(bcf_srs_t *files, const char *fname)
         }
     }
 
+    if ((auxdata = BCF_SR_AUX(files))) {
+        //store closure status for htsfile
+        int *tmp = realloc(auxdata->closefile, sizeof(int) * files->nreaders);
+        if (!tmp) {
+            hts_log_error("Failed to allocate memory");
+            return 0;
+        }
+        tmp[files->nreaders - 1] = autoclose;
+        auxdata->closefile = tmp;
+    }
+
+
     return 1;
 }
 
@@ -426,13 +458,15 @@ bcf_srs_t *bcf_sr_init(void)
     return files;
 }
 
-static void bcf_sr_destroy1(bcf_sr_t *reader)
+static void bcf_sr_destroy1(bcf_sr_t *reader, int closefile)
 {
     free(reader->fname);
     if ( reader->tbx_idx ) tbx_destroy(reader->tbx_idx);
     if ( reader->bcf_idx ) hts_idx_destroy(reader->bcf_idx);
     bcf_hdr_destroy(reader->header);
-    hts_close(reader->file);
+    if (closefile) {
+        hts_close(reader->file);
+    }
     if ( reader->itr ) tbx_itr_destroy(reader->itr);
     int j;
     for (j=0; j<reader->mbuffer; j++)
@@ -445,8 +479,10 @@ static void bcf_sr_destroy1(bcf_sr_t *reader)
 void bcf_sr_destroy(bcf_srs_t *files)
 {
     int i;
+    int *autoclose = BCF_SR_AUX(files)->closefile;
+
     for (i=0; i<files->nreaders; i++)
-        bcf_sr_destroy1(&files->readers[i]);
+        bcf_sr_destroy1(&files->readers[i], autoclose[i]);
     free(files->has_line);
     free(files->readers);
     for (i=0; i<files->n_smpl; i++) free(files->samples[i]);
@@ -456,19 +492,23 @@ void bcf_sr_destroy(bcf_srs_t *files)
     if (files->tmps.m) free(files->tmps.s);
     if (files->n_threads) bcf_sr_destroy_threads(files);
     bcf_sr_sort_destroy(&BCF_SR_AUX(files)->sort);
+    free(autoclose);
     free(files->aux);
     free(files);
 }
 
 void bcf_sr_remove_reader(bcf_srs_t *files, int i)
 {
     assert( !files->samples );  // not ready for this yet
+    int *autoclose = BCF_SR_AUX(files)->closefile;
+
     bcf_sr_sort_remove_reader(files, &BCF_SR_AUX(files)->sort, i);
-    bcf_sr_destroy1(&files->readers[i]);
+    bcf_sr_destroy1(&files->readers[i], autoclose[i]);
     if ( i+1 < files->nreaders )
     {
         memmove(&files->readers[i], &files->readers[i+1], (files->nreaders-i-1)*sizeof(bcf_sr_t));
         memmove(&files->has_line[i], &files->has_line[i+1], (files->nreaders-i-1)*sizeof(int));
+        memmove(&autoclose[i], &autoclose[i+1], (files->nreaders-i-1)*sizeof(int));
     }
     files->nreaders--;
 }

test/test-bcf-sr.c

@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2017, 2020, 2023 Genome Research Ltd.
+    Copyright (C) 2017, 2020, 2023, 2025 Genome Research Ltd.
 
     Author: Petr Danecek <[email protected]>
 
@@ -54,7 +54,7 @@ error(const char *format, ...)
 void HTS_NORETURN usage(int exit_code)
 {
     fprintf(stderr, "Usage: test-bcf-sr [OPTIONS] vcf-list.txt\n");
-    fprintf(stderr, "       test-bcf-sr [OPTIONS] -args file1.bcf [...]\n");
+    fprintf(stderr, "       test-bcf-sr [OPTIONS] --args file1.bcf [...]\n");
     fprintf(stderr, "Options:\n");
     fprintf(stderr, "       --args                   pass filenames directly in argument list\n");
     fprintf(stderr, "       --no-index               allow streaming\n");
@@ -63,6 +63,7 @@ void HTS_NORETURN usage(int exit_code)
     fprintf(stderr, "   -p, --pair <logic[+ref]>     logic: snps,indels,both,snps+ref,indels+ref,both+ref,exact,some,all\n");
     fprintf(stderr, "   -r, --regions <reg_list>     comma-separated list of regions\n");
     fprintf(stderr, "   -t, --targets <reg_list>     comma-separated list of targets\n");
+    fprintf(stderr, "   -u, --usefptr                use hfile pointer interface on reader addition\n");
     fprintf(stderr, "\n");
     exit(exit_code);
 }
@@ -133,13 +134,15 @@ int main(int argc, char *argv[])
         {"targets",required_argument,NULL,'t'},
         {"no-index",no_argument,NULL,1000},
         {"args",no_argument,NULL,1001},
+        {"usefptr",no_argument,NULL,'u'},
         {NULL,0,NULL,0}
     };
 
-    int c, pair = 0, use_index = 1, use_fofn = 1;
+    int c, pair = 0, use_index = 1, use_fofn = 1, usefptr = 0;
     enum htsExactFormat out_fmt = text_format; // for original pos + alleles
     const char *out_fn = NULL, *regions = NULL, *targets = NULL;
-    while ((c = getopt_long(argc, argv, "o:O:p:r:t:h", loptions, NULL)) >= 0)
+    htsFile **htsfp = NULL;
+    while ((c = getopt_long(argc, argv, "o:O:p:r:t:hu", loptions, NULL)) >= 0)
     {
         switch (c)
         {
@@ -179,6 +182,9 @@ int main(int argc, char *argv[])
             case 1001:
                 use_fofn = 0;
                 break;
+            case 'u':
+                usefptr = 1;    //use htsfile interface instead of fname i/f
+                break;
             case 'h':
                 usage(EXIT_SUCCESS);
             default: usage(EXIT_FAILURE);
@@ -218,8 +224,32 @@ int main(int argc, char *argv[])
             error("Failed to set targets\n");
     }
 
-    for (i=0; i<nvcf; i++)
-        if ( !bcf_sr_add_reader(sr,vcfs[i]) ) error("Failed to open %s: %s\n", vcfs[i],bcf_sr_strerror(sr->errnum));
+    if (usefptr && !(htsfp = malloc(sizeof(htsFile*) * nvcf))) {
+        error("Failed to allocate memory\n");
+    }
+
+    for (i=0; i<nvcf; i++) {
+        if (!usefptr) {
+            if ( !bcf_sr_add_reader(sr,vcfs[i]) ) {
+                error("Failed to open %s: %s\n", vcfs[i],
+                    bcf_sr_strerror(sr->errnum));
+            }
+        } else {    //use htsfile i/f
+            if (!(htsfp[i] = hts_open(vcfs[i], "r"))) {
+                error("Failed to open %s: %s\n", vcfs[i],
+                    bcf_sr_strerror(sr->errnum));
+            }
+            /*with name, index can be anywhere, named as anything
+              w/o name it has to be along with file with default naming*/
+
+            const char *idxname = strstr(vcfs[i], HTS_IDX_DELIM);
+            idxname += idxname ? sizeof(HTS_IDX_DELIM) - 1 : 0;
+            if ( !bcf_sr_add_hreader(sr, htsfp[i], 1, idxname) ) {
+                error("Failed to add reader %s: %s\n", vcfs[i],
+                    bcf_sr_strerror(sr->errnum));
+            }
+        }
+    }
 
     if (!sr->readers || sr->nreaders < 1)
         error("No readers set, even though one was added\n");
@@ -264,6 +294,10 @@ int main(int argc, char *argv[])
             free(vcfs[i]);
         free(vcfs);
     }
+    if (usefptr) {
+        //files are closed along with sr destroy
+        free(htsfp);
+    }
 
     return 0;
 }

test/test.pl

@@ -56,6 +56,7 @@
 run_test('test_bcf_sr_sort',$opts);
 run_test('test_bcf_sr_no_index',$opts);
 run_test('test_bcf_sr_range', $opts);
+run_test('test_bcf_sr_hreader', $opts);
 run_test('test_command',$opts,cmd=>'test-bcf-translate -',out=>'test-bcf-translate.out');
 run_test('test_convert_padded_header',$opts);
 run_test('test_rebgzip',$opts);
@@ -1345,6 +1346,34 @@ sub test_bcf_sr_range {
     }
 }
 
+sub test_bcf_sr_hreader {
+    #uses input file from test_bcf_sr_sort / test-bcf-sr.pl
+    #invokes bcf sync reader with hread method
+    my ($opts, %args) = @_;
+    my $test = "test_bcf_sr_hreader";
+    my $fail = 0;
+    my $cmd = "$$opts{path}/test-bcf-sr -p all $$opts{tmp}/list.txt -o $$opts{tmp}/file.out";
+    my $cmd_header = "$$opts{path}/test-bcf-sr -p all $$opts{tmp}/list.txt -o $$opts{tmp}/filenew.out -u";
+    my $cmd_diff = "diff $$opts{tmp}/filenew.out $$opts{tmp}/file.out";
+
+    my ($ret, $out) = _cmd($cmd);
+    if ($ret != 0) {
+        failed($opts, $test, "Failed to create reference output\n");
+        return;
+    }
+    ($ret, $out) = _cmd($cmd_header);
+    if ($ret != 0) {
+        failed($opts, $test, "Failed to create output\n");
+        return;
+    }
+    ($ret, $out) = _cmd($cmd_diff);
+    if ($ret != 0) {
+        failed($opts, $test, "Output differs to reference output\n");
+        return;
+    }
+    passed($opts, $test);
+}
+
 sub test_command
 {
     my ($opts, %args) = @_;