xref: /PHP-7.1/Zend/zend_smart_str.c (revision ccd4716e)
1 /*
2    +----------------------------------------------------------------------+
3    | PHP Version 7                                                        |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1997-2018 The PHP Group                                |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 3.01 of the PHP license,      |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.php.net/license/3_01.txt                                  |
11    | If you did not receive a copy of the PHP license and are unable to   |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@php.net so we can mail you a copy immediately.               |
14    +----------------------------------------------------------------------+
15    | Author: Dmitry Stogov <dmitry@zend.com>                              |
16    +----------------------------------------------------------------------+
17  */
18 
19 #include <zend.h>
20 #include "zend_smart_str.h"
21 
22 #define SMART_STR_OVERHEAD (ZEND_MM_OVERHEAD + _ZSTR_HEADER_SIZE)
23 
24 #ifndef SMART_STR_PAGE
25 # define SMART_STR_PAGE 4096
26 #endif
27 
28 #ifndef SMART_STR_START_SIZE
29 # define SMART_STR_START_SIZE (256 - SMART_STR_OVERHEAD - 1)
30 #endif
31 
32 #define SMART_STR_NEW_SIZE(len) \
33 	(((len + SMART_STR_OVERHEAD + SMART_STR_PAGE) & ~(SMART_STR_PAGE - 1)) - SMART_STR_OVERHEAD - 1)
34 
smart_str_erealloc(smart_str * str,size_t len)35 ZEND_API void ZEND_FASTCALL smart_str_erealloc(smart_str *str, size_t len)
36 {
37 	if (UNEXPECTED(!str->s)) {
38 		str->a = len < SMART_STR_START_SIZE
39 				? SMART_STR_START_SIZE
40 				: SMART_STR_NEW_SIZE(len);
41 		str->s = zend_string_alloc(str->a, 0);
42 		ZSTR_LEN(str->s) = 0;
43 	} else {
44 		str->a = SMART_STR_NEW_SIZE(len);
45 		str->s = (zend_string *) erealloc2(str->s, _ZSTR_HEADER_SIZE + str->a + 1, _ZSTR_HEADER_SIZE + ZSTR_LEN(str->s) + 1);
46 	}
47 }
48 
smart_str_realloc(smart_str * str,size_t len)49 ZEND_API void ZEND_FASTCALL smart_str_realloc(smart_str *str, size_t len)
50 {
51 	if (UNEXPECTED(!str->s)) {
52 		str->a = len < SMART_STR_START_SIZE
53 				? SMART_STR_START_SIZE
54 				: SMART_STR_NEW_SIZE(len);
55 		str->s = zend_string_alloc(str->a, 1);
56 		ZSTR_LEN(str->s) = 0;
57 	} else {
58 		str->a = SMART_STR_NEW_SIZE(len);
59 		str->s = (zend_string *) realloc(str->s, _ZSTR_HEADER_SIZE + str->a + 1);
60 	}
61 }
62 
63 /* Windows uses VK_ESCAPE instead of \e */
64 #ifndef VK_ESCAPE
65 #define VK_ESCAPE '\e'
66 #endif
67 
zend_compute_escaped_string_len(const char * s,size_t l)68 static size_t zend_compute_escaped_string_len(const char *s, size_t l) {
69 	size_t i, len = l;
70 	for (i = 0; i < l; ++i) {
71 		char c = s[i];
72 		if (c == '\n' || c == '\r' || c == '\t' ||
73 			c == '\f' || c == '\v' || c == '\\' || c == VK_ESCAPE) {
74 			len += 1;
75 		} else if (c < 32 || c > 126) {
76 			len += 3;
77 		}
78 	}
79 	return len;
80 }
81 
smart_str_append_escaped(smart_str * str,const char * s,size_t l)82 ZEND_API void ZEND_FASTCALL smart_str_append_escaped(smart_str *str, const char *s, size_t l) {
83 	char *res;
84 	size_t i, len = zend_compute_escaped_string_len(s, l);
85 
86 	smart_str_alloc(str, len, 0);
87 	res = &ZSTR_VAL(str->s)[ZSTR_LEN(str->s)];
88 	ZSTR_LEN(str->s) += len;
89 
90 	for (i = 0; i < l; ++i) {
91 		unsigned char c = s[i];
92 		if (c < 32 || c == '\\' || c > 126) {
93 			*res++ = '\\';
94 			switch (c) {
95 				case '\n': *res++ = 'n'; break;
96 				case '\r': *res++ = 'r'; break;
97 				case '\t': *res++ = 't'; break;
98 				case '\f': *res++ = 'f'; break;
99 				case '\v': *res++ = 'v'; break;
100 				case '\\': *res++ = '\\'; break;
101 				case VK_ESCAPE: *res++ = 'e'; break;
102 				default:
103 					*res++ = 'x';
104 					if ((c >> 4) < 10) {
105 						*res++ = (c >> 4) + '0';
106 					} else {
107 						*res++ = (c >> 4) + 'A' - 10;
108 					}
109 					if ((c & 0xf) < 10) {
110 						*res++ = (c & 0xf) + '0';
111 					} else {
112 						*res++ = (c & 0xf) + 'A' - 10;
113 					}
114 			}
115 		} else {
116 			*res++ = c;
117 		}
118 	}
119 }
120