src/buffer.h

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