xref: /lighttpd1.4/src/buffer.h (revision 3d04bc45)
1 #ifndef _BUFFER_H_
2 #define _BUFFER_H_
3 #include "first.h"
4 
5 #include "settings.h"
6 
7 #include <stdlib.h>
8 #include <sys/types.h>
9 #include <stdio.h>
10 #include <time.h>
11 
12 #if defined HAVE_STDINT_H
13 # include <stdint.h>
14 #elif defined HAVE_INTTYPES_H
15 # include <inttypes.h>
16 #endif
17 
18 /* generic string + binary data container; contains a terminating 0 in both
19  * cases
20  *
21  * used == 0 indicates a special "empty" state (unset config values); ptr
22  * might be NULL too then. otherwise an empty string has used == 1 (and ptr[0]
23  * == 0);
24  *
25  * copy/append functions will ensure used >= 1 (i.e. never leave it in the
26  * special empty state); only buffer_copy_buffer will copy the special empty
27  * state.
28  */
29 typedef struct {
30 	char *ptr;
31 
32 	/* "used" includes a terminating 0 */
33 	size_t used;
34 	/* size of allocated buffer at *ptr */
35 	size_t size;
36 } buffer;
37 
38 /* create new buffer; either empty or copy given data */
39 buffer* buffer_init(void);
40 buffer* buffer_init_buffer(const buffer *src); /* src can  be NULL */
41 buffer* buffer_init_string(const char *str); /* str can  be NULL */
42 
43 void buffer_free(buffer *b); /* b can be NULL */
44 /* truncates to used == 0; frees large buffers, might keep smaller ones for reuse */
45 void buffer_reset(buffer *b); /* b can be NULL */
46 
47 /* reset b. if NULL != b && NULL != src, move src content to b. reset src. */
48 void buffer_move(buffer *b, buffer *src);
49 
50 /* make sure buffer is large enough to store a string of given size
51  * and a terminating zero.
52  * sets b to an empty string, and may drop old content.
53  * @return b->ptr
54  */
55 char* buffer_string_prepare_copy(buffer *b, size_t size);
56 
57 /* allocate buffer large enough to be able to append a string of given size
58  * if b was empty (used == 0) it will contain an empty string (used == 1)
59  * afterwards
60  * "used" data is preserved; if not empty buffer must contain a
61  * zero terminated string.
62  */
63 char* buffer_string_prepare_append(buffer *b, size_t size);
64 
65 /* use after prepare_(copy,append) when you have written data to the buffer
66  * to increase the buffer length by size. also sets the terminating zero.
67  * requires enough space is present for the terminating zero (prepare with the
68  * same size to be sure).
69  */
70 void buffer_commit(buffer *b, size_t size);
71 
72 /* sets string length:
73  * - always stores a terminating zero to terminate the "new" string
74  * - does not modify the string data apart from terminating zero
75  * - reallocates the buffer iff needed
76  */
77 void buffer_string_set_length(buffer *b, size_t len);
78 
79 void buffer_copy_string(buffer *b, const char *s);
80 void buffer_copy_string_len(buffer *b, const char *s, size_t s_len);
81 void buffer_copy_buffer(buffer *b, const buffer *src);
82 /* convert input to hex and store in buffer */
83 void buffer_copy_string_hex(buffer *b, const char *in, size_t in_len);
84 
85 void buffer_append_string(buffer *b, const char *s);
86 void buffer_append_string_len(buffer *b, const char *s, size_t s_len);
87 void buffer_append_string_buffer(buffer *b, const buffer *src);
88 
89 void buffer_append_uint_hex(buffer *b, uintmax_t len);
90 void buffer_append_int(buffer *b, intmax_t val);
91 void buffer_copy_int(buffer *b, intmax_t val);
92 
93 void buffer_append_strftime(buffer *b, const char *format, const struct tm *tm);
94 
95 /* '-', log_10 (2^bits) = bits * log 2 / log 10 < bits * 0.31, terminating 0 */
96 #define LI_ITOSTRING_LENGTH (2 + (8 * sizeof(intmax_t) * 31 + 99) / 100)
97 
98 void li_itostrn(char *buf, size_t buf_len, intmax_t val);
99 void li_utostrn(char *buf, size_t buf_len, uintmax_t val);
100 
101 /* buf must be (at least) 2*s_len + 1 big. uses lower-case hex letters. */
102 void li_tohex(char *buf, size_t buf_len, const char *s, size_t s_len);
103 
104 char * buffer_search_string_len(buffer *b, const char *needle, size_t len);
105 
106 /* NULL buffer or empty buffer (used == 0);
107  * unset "string" (buffer) config options are initialized to used == 0,
108  * while setting an empty string leads to used == 1
109  */
110 int buffer_is_empty(const buffer *b);
111 /* NULL buffer, empty buffer (used == 0) or empty string (used == 1) */
112 int buffer_string_is_empty(const buffer *b);
113 
114 int buffer_is_equal(const buffer *a, const buffer *b);
115 int buffer_is_equal_right_len(const buffer *a, const buffer *b, size_t len);
116 int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len);
117 int buffer_is_equal_caseless_string(const buffer *a, const char *s, size_t b_len);
118 int buffer_caseless_compare(const char *a, size_t a_len, const char *b, size_t b_len);
119 
120 typedef enum {
121 	ENCODING_REL_URI, /* for coding a rel-uri (/with space/and%percent) nicely as part of a href */
122 	ENCODING_REL_URI_PART, /* same as ENC_REL_URL plus coding / too as %2F */
123 	ENCODING_HTML,         /* & becomes &amp; and so on */
124 	ENCODING_MINIMAL_XML,  /* minimal encoding for xml */
125 	ENCODING_HEX,          /* encode string as hex */
126 	ENCODING_HTTP_HEADER   /* encode \n with \t\n */
127 } buffer_encoding_t;
128 
129 void buffer_append_string_encoded(buffer *b, const char *s, size_t s_len, buffer_encoding_t encoding);
130 
131 /* escape non-printable characters; simple escapes for \t, \r, \n; fallback to \xCC */
132 void buffer_append_string_c_escaped(buffer *b, const char *s, size_t s_len);
133 
134 /* to upper case, replace non alpha-numerics with '_'; if is_http_header prefix with "HTTP_" unless s is "content-type" */
135 void buffer_copy_string_encoded_cgi_varnames(buffer *b, const char *s, size_t s_len, int is_http_header);
136 
137 void buffer_urldecode_path(buffer *url);
138 void buffer_urldecode_query(buffer *url);
139 void buffer_path_simplify(buffer *dest, buffer *src);
140 
141 void buffer_to_lower(buffer *b);
142 void buffer_to_upper(buffer *b);
143 
144 
145 /** deprecated */
146 char hex2int(unsigned char c);
147 char int2hex(char i);
148 
149 int light_isdigit(int c);
150 int light_isxdigit(int c);
151 int light_isalpha(int c);
152 int light_isalnum(int c);
153 
154 static inline size_t buffer_string_length(const buffer *b); /* buffer string length without terminating 0 */
155 static inline size_t buffer_string_space(const buffer *b); /* maximum length of string that can be stored without reallocating */
156 static inline void buffer_append_slash(buffer *b); /* append '/' no non-empty strings not ending in '/' */
157 
158 #define BUFFER_APPEND_STRING_CONST(x, y) \
159 	buffer_append_string_len(x, y, sizeof(y) - 1)
160 
161 #define BUFFER_COPY_STRING_CONST(x, y) \
162 	buffer_copy_string_len(x, y, sizeof(y) - 1)
163 
164 #define CONST_STR_LEN(x) x, (x) ? sizeof(x) - 1 : 0
165 #define CONST_BUF_LEN(x) ((x) ? (x)->ptr : NULL), buffer_string_length(x)
166 
167 
168 void print_backtrace(FILE *file);
169 void log_failed_assert(const char *filename, unsigned int line, const char *msg) LI_NORETURN;
170 #define force_assert(x) do { if (!(x)) log_failed_assert(__FILE__, __LINE__, "assertion failed: " #x); } while(0)
171 #define SEGFAULT() log_failed_assert(__FILE__, __LINE__, "aborted");
172 
173 /* inline implementations */
174 
175 static inline size_t buffer_string_length(const buffer *b) {
176 	return NULL != b && 0 != b->used ? b->used - 1 : 0;
177 }
178 
179 static inline size_t buffer_string_space(const buffer *b) {
180 	if (NULL == b || b->size == 0) return 0;
181 	if (0 == b->used) return b->size - 1;
182 	return b->size - b->used;
183 }
184 
185 static inline void buffer_append_slash(buffer *b) {
186 	size_t len = buffer_string_length(b);
187 	if (len > 0 && '/' != b->ptr[len-1]) BUFFER_APPEND_STRING_CONST(b, "/");
188 }
189 
190 #endif
191