comparison ezBAMQC/src/htslib/cram/string_alloc.c @ 0:dfa3745e5fd8

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author youngkim
date Thu, 24 Mar 2016 17:12:52 -0400
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1 /*
2 Copyright (c) 2010 Genome Research Ltd.
3 Author: Andrew Whitwham <aw7@sanger.ac.uk>
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
7
8 1. Redistributions of source code must retain the above copyright notice,
9 this list of conditions and the following disclaimer.
10
11 2. Redistributions in binary form must reproduce the above copyright notice,
12 this list of conditions and the following disclaimer in the documentation
13 and/or other materials provided with the distribution.
14
15 3. Neither the names Genome Research Ltd and Wellcome Trust Sanger
16 Institute nor the names of its contributors may be used to endorse or promote
17 products derived from this software without specific prior written permission.
18
19 THIS SOFTWARE IS PROVIDED BY GENOME RESEARCH LTD AND CONTRIBUTORS "AS IS" AND
20 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 DISCLAIMED. IN NO EVENT SHALL GENOME RESEARCH LTD OR CONTRIBUTORS BE LIABLE
23 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
26 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31
32 /*
33 A pooled string allocator intended to cut down on the
34 memory overhead of many small string allocations.
35
36 Andrew Whitwham, September 2010.
37 */
38
39 #include <string.h>
40 #include <stdlib.h>
41 #include <stdio.h>
42
43 #include "string_alloc.h"
44
45 #define MIN_STR_SIZE 1024
46
47
48 /* creates the string pool. max_length is the initial size
49 a single string can be. Tha max_length can grow as
50 needed */
51
52 string_alloc_t *string_pool_create(size_t max_length) {
53 string_alloc_t *a_str;
54
55 if (NULL == (a_str = (string_alloc_t *)malloc(sizeof(*a_str)))) {
56 return NULL;
57 }
58
59 if (max_length < MIN_STR_SIZE) max_length = MIN_STR_SIZE;
60
61 a_str->nstrings = 0;
62 a_str->max_length = max_length;
63 a_str->strings = NULL;
64
65 return a_str;
66 }
67
68
69 /* internal function to do the actual memory allocation */
70
71 static string_t *new_string_pool(string_alloc_t *a_str) {
72 string_t *str;
73
74 str = realloc(a_str->strings, (a_str->nstrings + 1) * sizeof(*a_str->strings));
75
76 if (NULL == str) return NULL;
77
78 a_str->strings = str;
79 str = &a_str->strings[a_str->nstrings];
80
81 str->str = malloc(a_str->max_length);;
82
83 if (NULL == str->str) return NULL;
84
85 str->used = 0;
86 a_str->nstrings++;
87
88 return str;
89 }
90
91
92 /* free allocated memory */
93
94 void string_pool_destroy(string_alloc_t *a_str) {
95 size_t i;
96
97 for (i = 0; i < a_str->nstrings; i++) {
98 free(a_str->strings[i].str);
99 }
100
101 free(a_str->strings);
102 free(a_str);
103 }
104
105
106 /* allocate space for a string */
107
108 char *string_alloc(string_alloc_t *a_str, size_t length) {
109 string_t *str;
110 char *ret;
111
112 if (length <= 0) return NULL;
113
114 // add to last string pool if we have space
115 if (a_str->nstrings) {
116 str = &a_str->strings[a_str->nstrings - 1];
117
118 if (str->used + length < a_str->max_length) {
119 ret = str->str + str->used;
120 str->used += length;
121 return ret;
122 }
123 }
124
125 // increase the max length if needs be
126 if (length > a_str->max_length) a_str->max_length = length;
127
128 // need a new string pool
129 str = new_string_pool(a_str);
130
131 if (NULL == str) return NULL;
132
133 str->used = length;
134 return str->str;
135 }
136
137
138 /* equivalent to strdup */
139
140 char *string_dup(string_alloc_t *a_str, char *instr) {
141 return string_ndup(a_str, instr, strlen(instr));
142 }
143
144 char *string_ndup(string_alloc_t *a_str, char *instr, size_t len) {
145 char *str = string_alloc(a_str, len + 1);
146
147 if (NULL == str) return NULL;
148
149 strncpy(str, instr, len);
150 str[len] = 0;
151
152 return str;
153 }