xref: /lighttpd1.4/src/buffer.h (revision bfaa4826)
1 #ifndef _BUFFER_H_
2 #define _BUFFER_H_
3 
4 #ifdef HAVE_CONFIG_H
5 # include "config.h"
6 #endif
7 
8 #include "settings.h"
9 
10 #include <stdlib.h>
11 #include <sys/types.h>
12 #include <stdio.h>
13 #include <time.h>
14 
15 #if defined HAVE_STDINT_H
16 # include <stdint.h>
17 #elif defined HAVE_INTTYPES_H
18 # include <inttypes.h>
19 #endif
20 
21 /* generic string + binary data container; contains a terminating 0 in both
22  * cases
23  *
24  * used == 0 indicates a special "empty" state (unset config values); ptr
25  * might be NULL too then. otherwise an empty string has used == 1 (and ptr[0]
26  * == 0);
27  *
28  * copy/append functions will ensure used >= 1 (i.e. never leave it in the
29  * special empty state); only buffer_copy_buffer will copy the special empty
30  * state.
31  */
32 typedef struct {
33 	char *ptr;
34 
35 	/* "used" includes a terminating 0 */
36 	size_t used;
37 	/* size of allocated buffer at *ptr */
38 	size_t size;
39 } buffer;
40 
41 /* create new buffer; either empty or copy given data */
42 buffer* buffer_init(void);
43 buffer* buffer_init_buffer(const buffer *src); /* src can  be NULL */
44 buffer* buffer_init_string(const char *str); /* str can  be NULL */
45 
46 void buffer_free(buffer *b); /* b can be NULL */
47 /* truncates to used == 0; frees large buffers, might keep smaller ones for reuse */
48 void buffer_reset(buffer *b); /* b can be NULL */
49 
50 /* reset b. if NULL != b && NULL != src, move src content to b. reset src. */
51 void buffer_move(buffer *b, buffer *src);
52 
53 /* make sure buffer is large enough to store a string of given size
54  * and a terminating zero.
55  * sets b to an empty string, and may drop old content.
56  * @return b->ptr
57  */
58 char* buffer_string_prepare_copy(buffer *b, size_t size);
59 
60 /* allocate buffer large enough to be able to append a string of given size
61  * if b was empty (used == 0) it will contain an empty string (used == 1)
62  * afterwards
63  * "used" data is preserved; if not empty buffer must contain a
64  * zero terminated string.
65  */
66 char* buffer_string_prepare_append(buffer *b, size_t size);
67 
68 /* use after prepare_(copy,append) when you have written data to the buffer
69  * to increase the buffer length by size. also sets the terminating zero.
70  * requires enough space is present for the terminating zero (prepare with the
71  * same size to be sure).
72  */
73 void buffer_commit(buffer *b, size_t size);
74 
75 /* sets string length:
76  * - always stores a terminating zero to terminate the "new" string
77  * - does not modify the string data apart from terminating zero
78  * - reallocates the buffer iff needed
79  */
80 void buffer_string_set_length(buffer *b, size_t len);
81 
82 void buffer_copy_string(buffer *b, const char *s);
83 void buffer_copy_string_len(buffer *b, const char *s, size_t s_len);
84 void buffer_copy_buffer(buffer *b, const buffer *src);
85 /* convert input to hex and store in buffer */
86 void buffer_copy_string_hex(buffer *b, const char *in, size_t in_len);
87 
88 void buffer_append_string(buffer *b, const char *s);
89 void buffer_append_string_len(buffer *b, const char *s, size_t s_len);
90 void buffer_append_string_buffer(buffer *b, const buffer *src);
91 
92 void buffer_append_uint_hex(buffer *b, uintmax_t len);
93 void buffer_append_int(buffer *b, intmax_t val);
94 void buffer_copy_int(buffer *b, intmax_t val);
95 
96 void buffer_append_strftime(buffer *b, const char *format, const struct tm *tm);
97 
98 /* '-', log_10 (2^bits) = bits * log 2 / log 10 < bits * 0.31, terminating 0 */
99 #define LI_ITOSTRING_LENGTH (2 + (8 * sizeof(intmax_t) * 31 + 99) / 100)
100 
101 void li_itostrn(char *buf, size_t buf_len, intmax_t val);
102 void li_itostr(char *buf, intmax_t val); /* buf must have at least LI_ITOSTRING_LENGTH bytes */
103 void li_utostrn(char *buf, size_t buf_len, uintmax_t val);
104 void li_utostr(char *buf, uintmax_t val); /* buf must have at least LI_ITOSTRING_LENGTH bytes */
105 
106 /* buf must be (at least) 2*s_len + 1 big. uses lower-case hex letters. */
107 void li_tohex(char *buf, const char *s, size_t s_len);
108 
109 char * buffer_search_string_len(buffer *b, const char *needle, size_t len);
110 
111 /* NULL buffer or empty buffer (used == 0);
112  * unset "string" (buffer) config options are initialized to used == 0,
113  * while setting an empty string leads to used == 1
114  */
115 int buffer_is_empty(const buffer *b);
116 /* NULL buffer, empty buffer (used == 0) or empty string (used == 1) */
117 int buffer_string_is_empty(const buffer *b);
118 
119 int buffer_is_equal(const buffer *a, const buffer *b);
120 int buffer_is_equal_right_len(const buffer *a, const buffer *b, size_t len);
121 int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len);
122 int buffer_is_equal_caseless_string(const buffer *a, const char *s, size_t b_len);
123 int buffer_caseless_compare(const char *a, size_t a_len, const char *b, size_t b_len);
124 
125 typedef enum {
126 	ENCODING_REL_URI, /* for coding a rel-uri (/with space/and%percent) nicely as part of a href */
127 	ENCODING_REL_URI_PART, /* same as ENC_REL_URL plus coding / too as %2F */
128 	ENCODING_HTML,         /* & becomes &amp; and so on */
129 	ENCODING_MINIMAL_XML,  /* minimal encoding for xml */
130 	ENCODING_HEX,          /* encode string as hex */
131 	ENCODING_HTTP_HEADER   /* encode \n with \t\n */
132 } buffer_encoding_t;
133 
134 void buffer_append_string_encoded(buffer *b, const char *s, size_t s_len, buffer_encoding_t encoding);
135 
136 /* escape non-printable characters; simple escapes for \t, \r, \n; fallback to \xCC */
137 void buffer_append_string_c_escaped(buffer *b, const char *s, size_t s_len);
138 
139 /* to upper case, replace non alpha-numerics with '_'; if is_http_header prefix with "HTTP_" unless s is "content-type" */
140 void buffer_copy_string_encoded_cgi_varnames(buffer *b, const char *s, size_t s_len, int is_http_header);
141 
142 void buffer_urldecode_path(buffer *url);
143 void buffer_urldecode_query(buffer *url);
144 void buffer_path_simplify(buffer *dest, buffer *src);
145 
146 void buffer_to_lower(buffer *b);
147 void buffer_to_upper(buffer *b);
148 
149 
150 /** deprecated */
151 char hex2int(unsigned char c);
152 char int2hex(char i);
153 
154 int light_isdigit(int c);
155 int light_isxdigit(int c);
156 int light_isalpha(int c);
157 int light_isalnum(int c);
158 
159 static inline size_t buffer_string_length(const buffer *b); /* buffer string length without terminating 0 */
160 static inline size_t buffer_string_space(const buffer *b); /* maximum length of string that can be stored without reallocating */
161 static inline void buffer_append_slash(buffer *b); /* append '/' no non-empty strings not ending in '/' */
162 
163 #define BUFFER_APPEND_STRING_CONST(x, y) \
164 	buffer_append_string_len(x, y, sizeof(y) - 1)
165 
166 #define BUFFER_COPY_STRING_CONST(x, y) \
167 	buffer_copy_string_len(x, y, sizeof(y) - 1)
168 
169 #define CONST_STR_LEN(x) x, (x) ? sizeof(x) - 1 : 0
170 #define CONST_BUF_LEN(x) ((x) ? (x)->ptr : NULL), buffer_string_length(x)
171 
172 
173 void print_backtrace(FILE *file);
174 void log_failed_assert(const char *filename, unsigned int line, const char *msg) LI_NORETURN;
175 #define force_assert(x) do { if (!(x)) log_failed_assert(__FILE__, __LINE__, "assertion failed: " #x); } while(0)
176 #define SEGFAULT() log_failed_assert(__FILE__, __LINE__, "aborted");
177 
178 /* inline implementations */
179 
180 static inline size_t buffer_string_length(const buffer *b) {
181 	return NULL != b && 0 != b->used ? b->used - 1 : 0;
182 }
183 
184 static inline size_t buffer_string_space(const buffer *b) {
185 	if (NULL == b || b->size == 0) return 0;
186 	if (0 == b->used) return b->size - 1;
187 	return b->size - b->used;
188 }
189 
190 static inline void buffer_append_slash(buffer *b) {
191 	size_t len = buffer_string_length(b);
192 	if (len > 0 && '/' != b->ptr[len-1]) BUFFER_APPEND_STRING_CONST(b, "/");
193 }
194 
195 #endif
196