Imported Upstream version 0.6
[pysam.git] / samtools / bam_import.c.pysam.c
1 #include "pysam.h"
2
3 #include <zlib.h>
4 #include <stdio.h>
5 #include <ctype.h>
6 #include <string.h>
7 #include <stdlib.h>
8 #include <unistd.h>
9 #include <assert.h>
10 #ifdef _WIN32
11 #include <fcntl.h>
12 #endif
13 #include "kstring.h"
14 #include "bam.h"
15 #include "sam_header.h"
16 #include "kseq.h"
17 #include "khash.h"
18
19 KSTREAM_INIT(gzFile, gzread, 16384)
20 KHASH_MAP_INIT_STR(ref, uint64_t)
21
22 void bam_init_header_hash(bam_header_t *header);
23 void bam_destroy_header_hash(bam_header_t *header);
24 int32_t bam_get_tid(const bam_header_t *header, const char *seq_name);
25
26 unsigned char bam_nt16_table[256] = {
27         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
28         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
29         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
30          1, 2, 4, 8, 15,15,15,15, 15,15,15,15, 15, 0 /*=*/,15,15,
31         15, 1,14, 2, 13,15,15, 4, 11,15,15,12, 15, 3,15,15,
32         15,15, 5, 6,  8,15, 7, 9, 15,10,15,15, 15,15,15,15,
33         15, 1,14, 2, 13,15,15, 4, 11,15,15,12, 15, 3,15,15,
34         15,15, 5, 6,  8,15, 7, 9, 15,10,15,15, 15,15,15,15,
35         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
36         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
37         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
38         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
39         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
40         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
41         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
42         15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15
43 };
44
45 unsigned short bam_char2flag_table[256] = {
46         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
47         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
48         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
49         0,BAM_FREAD1,BAM_FREAD2,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
50         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
51         BAM_FPROPER_PAIR,0,BAM_FMREVERSE,0, 0,BAM_FMUNMAP,0,0, 0,0,0,0, 0,0,0,0,
52         0,0,0,0, BAM_FDUP,0,BAM_FQCFAIL,0, 0,0,0,0, 0,0,0,0,
53         BAM_FPAIRED,0,BAM_FREVERSE,BAM_FSECONDARY, 0,BAM_FUNMAP,0,0, 0,0,0,0, 0,0,0,0,
54         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
55         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
56         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
57         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
58         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
59         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
60         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
61         0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0
62 };
63
64 char *bam_nt16_rev_table = "=ACMGRSVTWYHKDBN";
65
66 struct __tamFile_t {
67         gzFile fp;
68         kstream_t *ks;
69         kstring_t *str;
70         uint64_t n_lines;
71         int is_first;
72 };
73
74 char **__bam_get_lines(const char *fn, int *_n) // for bam_plcmd.c only
75 {
76         char **list = 0, *s;
77         int n = 0, dret, m = 0;
78         gzFile fp = (strcmp(fn, "-") == 0)? gzdopen(fileno(stdin), "r") : gzopen(fn, "r");
79         kstream_t *ks;
80         kstring_t *str;
81         str = (kstring_t*)calloc(1, sizeof(kstring_t));
82         ks = ks_init(fp);
83         while (ks_getuntil(ks, '\n', str, &dret) > 0) {
84                 if (n == m) {
85                         m = m? m << 1 : 16;
86                         list = (char**)realloc(list, m * sizeof(char*));
87                 }
88                 if (str->s[str->l-1] == '\r')
89                         str->s[--str->l] = '\0';
90                 s = list[n++] = (char*)calloc(str->l + 1, 1);
91                 strcpy(s, str->s);
92         }
93         ks_destroy(ks);
94         gzclose(fp);
95         free(str->s); free(str);
96         *_n = n;
97         return list;
98 }
99
100 static bam_header_t *hash2header(const kh_ref_t *hash)
101 {
102         bam_header_t *header;
103         khiter_t k;
104         header = bam_header_init();
105         header->n_targets = kh_size(hash);
106         header->target_name = (char**)calloc(kh_size(hash), sizeof(char*));
107         header->target_len = (uint32_t*)calloc(kh_size(hash), 4);
108         for (k = kh_begin(hash); k != kh_end(hash); ++k) {
109                 if (kh_exist(hash, k)) {
110                         int i = (int)kh_value(hash, k);
111                         header->target_name[i] = (char*)kh_key(hash, k);
112                         header->target_len[i] = kh_value(hash, k)>>32;
113                 }
114         }
115         bam_init_header_hash(header);
116         return header;
117 }
118 bam_header_t *sam_header_read2(const char *fn)
119 {
120         bam_header_t *header;
121         int c, dret, ret, error = 0;
122         gzFile fp;
123         kstream_t *ks;
124         kstring_t *str;
125         kh_ref_t *hash;
126         khiter_t k;
127         if (fn == 0) return 0;
128         fp = (strcmp(fn, "-") == 0)? gzdopen(fileno(stdin), "r") : gzopen(fn, "r");
129         if (fp == 0) return 0;
130         hash = kh_init(ref);
131         ks = ks_init(fp);
132         str = (kstring_t*)calloc(1, sizeof(kstring_t));
133         while (ks_getuntil(ks, 0, str, &dret) > 0) {
134                 char *s = strdup(str->s);
135                 int len, i;
136                 i = kh_size(hash);
137                 ks_getuntil(ks, 0, str, &dret);
138                 len = atoi(str->s);
139                 k = kh_put(ref, hash, s, &ret);
140                 if (ret == 0) {
141                         fprintf(pysamerr, "[sam_header_read2] duplicated sequence name: %s\n", s);
142                         error = 1;
143                 }
144                 kh_value(hash, k) = (uint64_t)len<<32 | i;
145                 if (dret != '\n')
146                         while ((c = ks_getc(ks)) != '\n' && c != -1);
147         }
148         ks_destroy(ks);
149         gzclose(fp);
150         free(str->s); free(str);
151         fprintf(pysamerr, "[sam_header_read2] %d sequences loaded.\n", kh_size(hash));
152         if (error) return 0;
153         header = hash2header(hash);
154         kh_destroy(ref, hash);
155         return header;
156 }
157 static inline uint8_t *alloc_data(bam1_t *b, int size)
158 {
159         if (b->m_data < size) {
160                 b->m_data = size;
161                 kroundup32(b->m_data);
162                 b->data = (uint8_t*)realloc(b->data, b->m_data);
163         }
164         return b->data;
165 }
166 static inline void parse_error(int64_t n_lines, const char * __restrict msg)
167 {
168         fprintf(pysamerr, "Parse error at line %lld: %s\n", (long long)n_lines, msg);
169         abort();
170 }
171 static inline void append_text(bam_header_t *header, kstring_t *str)
172 {
173         size_t x = header->l_text, y = header->l_text + str->l + 2; // 2 = 1 byte dret + 1 byte null
174         kroundup32(x); kroundup32(y);
175         if (x < y) 
176     {
177         header->n_text = y;
178         header->text = (char*)realloc(header->text, y);
179         if ( !header->text ) 
180         {
181             fprintf(pysamerr,"realloc failed to alloc %ld bytes\n", y);
182             abort();
183         }
184     }
185     // Sanity check
186     if ( header->l_text+str->l+1 >= header->n_text )
187     {
188         fprintf(pysamerr,"append_text FIXME: %ld>=%ld, x=%ld,y=%ld\n",  header->l_text+str->l+1,header->n_text,x,y);
189         abort();
190     }
191         strncpy(header->text + header->l_text, str->s, str->l+1); // we cannot use strcpy() here.
192         header->l_text += str->l + 1;
193         header->text[header->l_text] = 0;
194 }
195
196 int sam_header_parse(bam_header_t *h)
197 {
198         char **tmp;
199         int i;
200         free(h->target_len); free(h->target_name);
201         h->n_targets = 0; h->target_len = 0; h->target_name = 0;
202         if (h->l_text < 3) return 0;
203         if (h->dict == 0) h->dict = sam_header_parse2(h->text);
204         tmp = sam_header2list(h->dict, "SQ", "SN", &h->n_targets);
205         if (h->n_targets == 0) return 0;
206         h->target_name = calloc(h->n_targets, sizeof(void*));
207         for (i = 0; i < h->n_targets; ++i)
208                 h->target_name[i] = strdup(tmp[i]);
209         free(tmp);
210         tmp = sam_header2list(h->dict, "SQ", "LN", &h->n_targets);
211         h->target_len = calloc(h->n_targets, 4);
212         for (i = 0; i < h->n_targets; ++i)
213                 h->target_len[i] = atoi(tmp[i]);
214         free(tmp);
215         return h->n_targets;
216 }
217
218 bam_header_t *sam_header_read(tamFile fp)
219 {
220         int ret, dret;
221         bam_header_t *header = bam_header_init();
222         kstring_t *str = fp->str;
223         while ((ret = ks_getuntil(fp->ks, KS_SEP_TAB, str, &dret)) >= 0 && str->s[0] == '@') { // skip header
224                 str->s[str->l] = dret; // note that str->s is NOT null terminated!!
225                 append_text(header, str);
226                 if (dret != '\n') {
227                         ret = ks_getuntil(fp->ks, '\n', str, &dret);
228                         str->s[str->l] = '\n'; // NOT null terminated!!
229                         append_text(header, str);
230                 }
231                 ++fp->n_lines;
232         }
233         sam_header_parse(header);
234         bam_init_header_hash(header);
235         fp->is_first = 1;
236         return header;
237 }
238
239 int sam_read1(tamFile fp, bam_header_t *header, bam1_t *b)
240 {
241         int ret, doff, doff0, dret, z = 0;
242         bam1_core_t *c = &b->core;
243         kstring_t *str = fp->str;
244         kstream_t *ks = fp->ks;
245
246         if (fp->is_first) {
247                 fp->is_first = 0;
248                 ret = str->l;
249         } else {
250                 do { // special consideration for empty lines
251                         ret = ks_getuntil(fp->ks, KS_SEP_TAB, str, &dret);
252                         if (ret >= 0) z += str->l + 1;
253                 } while (ret == 0);
254         }
255         if (ret < 0) return -1;
256         ++fp->n_lines;
257         doff = 0;
258
259         { // name
260                 c->l_qname = strlen(str->s) + 1;
261                 memcpy(alloc_data(b, doff + c->l_qname) + doff, str->s, c->l_qname);
262                 doff += c->l_qname;
263         }
264         { // flag
265                 long flag;
266                 char *s;
267                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1;
268                 flag = strtol((char*)str->s, &s, 0);
269                 if (*s) { // not the end of the string
270                         flag = 0;
271                         for (s = str->s; *s; ++s)
272                                 flag |= bam_char2flag_table[(int)*s];
273                 }
274                 c->flag = flag;
275         }
276         { // tid, pos, qual
277                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1; c->tid = bam_get_tid(header, str->s);
278                 if (c->tid < 0 && strcmp(str->s, "*")) {
279                         if (header->n_targets == 0) {
280                                 fprintf(pysamerr, "[sam_read1] missing header? Abort!\n");
281                                 exit(1);
282                         } else fprintf(pysamerr, "[sam_read1] reference '%s' is recognized as '*'.\n", str->s);
283                 }
284                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1; c->pos = isdigit(str->s[0])? atoi(str->s) - 1 : -1;
285                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1; c->qual = isdigit(str->s[0])? atoi(str->s) : 0;
286                 if (ret < 0) return -2;
287         }
288         { // cigar
289                 char *s, *t;
290                 int i, op;
291                 long x;
292                 c->n_cigar = 0;
293                 if (ks_getuntil(ks, KS_SEP_TAB, str, &dret) < 0) return -3;
294                 z += str->l + 1;
295                 if (str->s[0] != '*') {
296                         for (s = str->s; *s; ++s) {
297                                 if ((isalpha(*s)) || (*s=='=')) ++c->n_cigar;
298                                 else if (!isdigit(*s)) parse_error(fp->n_lines, "invalid CIGAR character");
299                         }
300                         b->data = alloc_data(b, doff + c->n_cigar * 4);
301                         for (i = 0, s = str->s; i != c->n_cigar; ++i) {
302                                 x = strtol(s, &t, 10);
303                                 op = toupper(*t);
304                                 if (op == 'M') op = BAM_CMATCH;
305                                 else if (op == 'I') op = BAM_CINS;
306                                 else if (op == 'D') op = BAM_CDEL;
307                                 else if (op == 'N') op = BAM_CREF_SKIP;
308                                 else if (op == 'S') op = BAM_CSOFT_CLIP;
309                                 else if (op == 'H') op = BAM_CHARD_CLIP;
310                                 else if (op == 'P') op = BAM_CPAD;
311                                 else if (op == '=') op = BAM_CEQUAL;
312                                 else if (op == 'X') op = BAM_CDIFF;
313                                 else parse_error(fp->n_lines, "invalid CIGAR operation");
314                                 s = t + 1;
315                                 bam1_cigar(b)[i] = x << BAM_CIGAR_SHIFT | op;
316                         }
317                         if (*s) parse_error(fp->n_lines, "unmatched CIGAR operation");
318                         c->bin = bam_reg2bin(c->pos, bam_calend(c, bam1_cigar(b)));
319                         doff += c->n_cigar * 4;
320                 } else {
321                         if (!(c->flag&BAM_FUNMAP)) {
322                                 fprintf(pysamerr, "Parse warning at line %lld: mapped sequence without CIGAR\n", (long long)fp->n_lines);
323                                 c->flag |= BAM_FUNMAP;
324                         }
325                         c->bin = bam_reg2bin(c->pos, c->pos + 1);
326                 }
327         }
328         { // mtid, mpos, isize
329                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1;
330                 c->mtid = strcmp(str->s, "=")? bam_get_tid(header, str->s) : c->tid;
331                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1;
332                 c->mpos = isdigit(str->s[0])? atoi(str->s) - 1 : -1;
333                 ret = ks_getuntil(ks, KS_SEP_TAB, str, &dret); z += str->l + 1;
334                 c->isize = (str->s[0] == '-' || isdigit(str->s[0]))? atoi(str->s) : 0;
335                 if (ret < 0) return -4;
336         }
337         { // seq and qual
338                 int i;
339                 uint8_t *p = 0;
340                 if (ks_getuntil(ks, KS_SEP_TAB, str, &dret) < 0) return -5; // seq
341                 z += str->l + 1;
342                 if (strcmp(str->s, "*")) {
343                         c->l_qseq = strlen(str->s);
344                         if (c->n_cigar && c->l_qseq != (int32_t)bam_cigar2qlen(c, bam1_cigar(b))) {
345                           fprintf(pysamerr, "Line %ld, sequence length %i vs %i from CIGAR\n",
346                                   (long)fp->n_lines, c->l_qseq, (int32_t)bam_cigar2qlen(c, bam1_cigar(b)));
347                           parse_error(fp->n_lines, "CIGAR and sequence length are inconsistent");
348                         }
349                         p = (uint8_t*)alloc_data(b, doff + c->l_qseq + (c->l_qseq+1)/2) + doff;
350                         memset(p, 0, (c->l_qseq+1)/2);
351                         for (i = 0; i < c->l_qseq; ++i)
352                                 p[i/2] |= bam_nt16_table[(int)str->s[i]] << 4*(1-i%2);
353                 } else c->l_qseq = 0;
354                 if (ks_getuntil(ks, KS_SEP_TAB, str, &dret) < 0) return -6; // qual
355                 z += str->l + 1;
356                 if (strcmp(str->s, "*") && c->l_qseq != strlen(str->s))
357                         parse_error(fp->n_lines, "sequence and quality are inconsistent");
358                 p += (c->l_qseq+1)/2;
359                 if (strcmp(str->s, "*") == 0) for (i = 0; i < c->l_qseq; ++i) p[i] = 0xff;
360                 else for (i = 0; i < c->l_qseq; ++i) p[i] = str->s[i] - 33;
361                 doff += c->l_qseq + (c->l_qseq+1)/2;
362         }
363         doff0 = doff;
364         if (dret != '\n' && dret != '\r') { // aux
365                 while (ks_getuntil(ks, KS_SEP_TAB, str, &dret) >= 0) {
366                         uint8_t *s, type, key[2];
367                         z += str->l + 1;
368                         if (str->l < 6 || str->s[2] != ':' || str->s[4] != ':')
369                                 parse_error(fp->n_lines, "missing colon in auxiliary data");
370                         key[0] = str->s[0]; key[1] = str->s[1];
371                         type = str->s[3];
372                         s = alloc_data(b, doff + 3) + doff;
373                         s[0] = key[0]; s[1] = key[1]; s += 2; doff += 2;
374                         if (type == 'A' || type == 'a' || type == 'c' || type == 'C') { // c and C for backward compatibility
375                                 s = alloc_data(b, doff + 2) + doff;
376                                 *s++ = 'A'; *s = str->s[5];
377                                 doff += 2;
378                         } else if (type == 'I' || type == 'i') {
379                                 long long x;
380                                 s = alloc_data(b, doff + 5) + doff;
381                                 x = (long long)atoll(str->s + 5);
382                                 if (x < 0) {
383                                         if (x >= -127) {
384                                                 *s++ = 'c'; *(int8_t*)s = (int8_t)x;
385                                                 s += 1; doff += 2;
386                                         } else if (x >= -32767) {
387                                                 *s++ = 's'; *(int16_t*)s = (int16_t)x;
388                                                 s += 2; doff += 3;
389                                         } else {
390                                                 *s++ = 'i'; *(int32_t*)s = (int32_t)x;
391                                                 s += 4; doff += 5;
392                                                 if (x < -2147483648ll)
393                                                         fprintf(pysamerr, "Parse warning at line %lld: integer %lld is out of range.",
394                                                                         (long long)fp->n_lines, x);
395                                         }
396                                 } else {
397                                         if (x <= 255) {
398                                                 *s++ = 'C'; *s++ = (uint8_t)x;
399                                                 doff += 2;
400                                         } else if (x <= 65535) {
401                                                 *s++ = 'S'; *(uint16_t*)s = (uint16_t)x;
402                                                 s += 2; doff += 3;
403                                         } else {
404                                                 *s++ = 'I'; *(uint32_t*)s = (uint32_t)x;
405                                                 s += 4; doff += 5;
406                                                 if (x > 4294967295ll)
407                                                         fprintf(pysamerr, "Parse warning at line %lld: integer %lld is out of range.",
408                                                                         (long long)fp->n_lines, x);
409                                         }
410                                 }
411                         } else if (type == 'f') {
412                                 s = alloc_data(b, doff + 5) + doff;
413                                 *s++ = 'f';
414                                 *(float*)s = (float)atof(str->s + 5);
415                                 s += 4; doff += 5;
416                         } else if (type == 'd') {
417                                 s = alloc_data(b, doff + 9) + doff;
418                                 *s++ = 'd';
419                                 *(float*)s = (float)atof(str->s + 9);
420                                 s += 8; doff += 9;
421                         } else if (type == 'Z' || type == 'H') {
422                                 int size = 1 + (str->l - 5) + 1;
423                                 if (type == 'H') { // check whether the hex string is valid
424                                         int i;
425                                         if ((str->l - 5) % 2 == 1) parse_error(fp->n_lines, "length of the hex string not even");
426                                         for (i = 0; i < str->l - 5; ++i) {
427                                                 int c = toupper(str->s[5 + i]);
428                                                 if (!((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')))
429                                                         parse_error(fp->n_lines, "invalid hex character");
430                                         }
431                                 }
432                                 s = alloc_data(b, doff + size) + doff;
433                                 *s++ = type;
434                                 memcpy(s, str->s + 5, str->l - 5);
435                                 s[str->l - 5] = 0;
436                                 doff += size;
437                         } else if (type == 'B') {
438                                 int32_t n = 0, Bsize, k = 0, size;
439                                 char *p;
440                                 if (str->l < 8) parse_error(fp->n_lines, "too few values in aux type B");
441                                 Bsize = bam_aux_type2size(str->s[5]); // the size of each element
442                                 for (p = (char*)str->s + 6; *p; ++p) // count the number of elements in the array
443                                         if (*p == ',') ++n;
444                                 p = str->s + 7; // now p points to the first number in the array
445                                 size = 6 + Bsize * n; // total number of bytes allocated to this tag
446                                 s = alloc_data(b, doff + 6 * Bsize * n) + doff; // allocate memory
447                                 *s++ = 'B'; *s++ = str->s[5];
448                                 memcpy(s, &n, 4); s += 4; // write the number of elements
449                                 if (str->s[5] == 'c')      while (p < str->s + str->l) ((int8_t*)s)[k++]   = (int8_t)strtol(p, &p, 0),   ++p;
450                                 else if (str->s[5] == 'C') while (p < str->s + str->l) ((uint8_t*)s)[k++]  = (uint8_t)strtol(p, &p, 0),  ++p;
451                                 else if (str->s[5] == 's') while (p < str->s + str->l) ((int16_t*)s)[k++]  = (int16_t)strtol(p, &p, 0),  ++p; // FIXME: avoid unaligned memory
452                                 else if (str->s[5] == 'S') while (p < str->s + str->l) ((uint16_t*)s)[k++] = (uint16_t)strtol(p, &p, 0), ++p;
453                                 else if (str->s[5] == 'i') while (p < str->s + str->l) ((int32_t*)s)[k++]  = (int32_t)strtol(p, &p, 0),  ++p;
454                                 else if (str->s[5] == 'I') while (p < str->s + str->l) ((uint32_t*)s)[k++] = (uint32_t)strtol(p, &p, 0), ++p;
455                                 else if (str->s[5] == 'f') while (p < str->s + str->l) ((float*)s)[k++]    = (float)strtod(p, &p),       ++p;
456                                 else parse_error(fp->n_lines, "unrecognized array type");
457                                 s += Bsize * n; doff += size;
458                         } else parse_error(fp->n_lines, "unrecognized type");
459                         if (dret == '\n' || dret == '\r') break;
460                 }
461         }
462         b->l_aux = doff - doff0;
463         b->data_len = doff;
464         return z;
465 }
466
467 tamFile sam_open(const char *fn)
468 {
469         tamFile fp;
470         gzFile gzfp = (strcmp(fn, "-") == 0)? gzdopen(fileno(stdin), "rb") : gzopen(fn, "rb");
471         if (gzfp == 0) return 0;
472         fp = (tamFile)calloc(1, sizeof(struct __tamFile_t));
473         fp->str = (kstring_t*)calloc(1, sizeof(kstring_t));
474         fp->fp = gzfp;
475         fp->ks = ks_init(fp->fp);
476         return fp;
477 }
478
479 void sam_close(tamFile fp)
480 {
481         if (fp) {
482                 ks_destroy(fp->ks);
483                 gzclose(fp->fp);
484                 free(fp->str->s); free(fp->str);
485                 free(fp);
486         }
487 }