1 /*
2  line-split.c : irssi
3 
4     Copyright (C) 1999-2000 Timo Sirainen
5 
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10 
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15 
16     You should have received a copy of the GNU General Public License along
17     with this program; if not, write to the Free Software Foundation, Inc.,
18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20 
21 #include "module.h"
22 #include "misc.h"
23 
24 /* Maximum line length - split to two lines if it's longer than this.
25 
26    This is mostly to prevent excessive memory usage. Like if someone DCC
27    chats you, you both have very fast connections and the other side sends
28    you 100 megs of text without any line feeds -> irssi will (try to)
29    allocate 128M of memory for the line and will eventually crash when it
30    can't allocate any more memory. If the line is split at every 64k the
31    text buffer will free the old lines and the memory usage never gets
32    too high. */
33 #define MAX_CHARS_IN_LINE 65536
34 
35 struct _LINEBUF_REC {
36         int len;
37 	int alloc;
38 	int remove;
39         char *str;
40 };
41 
linebuf_append(LINEBUF_REC * rec,const char * data,int len)42 static void linebuf_append(LINEBUF_REC *rec, const char *data, int len)
43 {
44 	if (rec->len+len > rec->alloc) {
45 		rec->alloc = nearest_power(rec->len+len);;
46 		rec->str = g_realloc(rec->str, rec->alloc);
47 	}
48 
49 	memcpy(rec->str + rec->len, data, len);
50 	rec->len += len;
51 }
52 
linebuf_find(LINEBUF_REC * rec,char chr)53 static char *linebuf_find(LINEBUF_REC *rec, char chr)
54 {
55 	return memchr(rec->str, chr, rec->len);
56 }
57 
remove_newline(LINEBUF_REC * rec)58 static int remove_newline(LINEBUF_REC *rec)
59 {
60 	char *ptr;
61 
62 	ptr = linebuf_find(rec, '\n');
63 	if (ptr == NULL) {
64 		/* LF wasn't found, wait for more data.. */
65 		if (rec->len < MAX_CHARS_IN_LINE)
66 			return 0;
67 
68 		/* line buffer is too big - force a newline. */
69                 linebuf_append(rec, "\n", 1);
70 		ptr = rec->str+rec->len-1;
71 	}
72 
73 	rec->remove = (int) (ptr-rec->str)+1;
74 	if (ptr != rec->str && ptr[-1] == '\r') {
75 		/* remove CR too. */
76 		ptr--;
77 	}
78 
79 	*ptr = '\0';
80 	return 1;
81 }
82 
83 /* line-split `data'. Initially `*buffer' should contain NULL. */
line_split(const char * data,int len,char ** output,LINEBUF_REC ** buffer)84 int line_split(const char *data, int len, char **output, LINEBUF_REC **buffer)
85 {
86 	LINEBUF_REC *rec;
87 	int ret;
88 
89 	g_return_val_if_fail(data != NULL, -1);
90 	g_return_val_if_fail(output != NULL, -1);
91 	g_return_val_if_fail(buffer != NULL, -1);
92 
93 	if (*buffer == NULL)
94 		*buffer = g_new0(LINEBUF_REC, 1);
95 	rec = *buffer;
96 
97 	if (rec->remove > 0) {
98 		rec->len -= rec->remove;
99 		g_memmove(rec->str, rec->str+rec->remove, rec->len);
100 		rec->remove = 0;
101 	}
102 
103 	if (len > 0)
104 		linebuf_append(rec, data, len);
105 	else if (len < 0) {
106 		/* connection closed.. */
107 		if (rec->len == 0)
108 			return -1;
109 
110 		/* no new data got but still something in buffer.. */
111 		if (linebuf_find(rec, '\n') == NULL) {
112 			/* connection closed and last line is missing \n ..
113 			   just add it so we can see if it had
114 			   anything useful.. */
115 			linebuf_append(rec, "\n", 1);
116 		}
117 	}
118 
119 	ret = remove_newline(rec);
120 	*output = rec->str;
121 	return ret;
122 }
123 
line_split_free(LINEBUF_REC * buffer)124 void line_split_free(LINEBUF_REC *buffer)
125 {
126 	if (buffer != NULL) {
127 		if (buffer->str != NULL) g_free(buffer->str);
128 		g_free(buffer);
129 	}
130 }
131 
132 /* Return 1 if there is no data in the buffer */
line_split_is_empty(LINEBUF_REC * buffer)133 int line_split_is_empty(LINEBUF_REC *buffer)
134 {
135 	return buffer->len == 0;
136 }
137