Annotation of margi2/ringbuffy.c, revision 1.4
1.1 cvs 1: /*
2: ringbuffy.c
3:
4: Copyright (C) Marcus Metzler for convergence integrated media.
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
17: along with this program; if not, write to the Free Software
18: Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19: */
20:
21: #define __NO_VERSION__
22:
23: #include "margi.h"
24: #include "ringbuffy.h"
25:
26: int ring_init (ringbuffy *rbuf, long size)
27: {
1.4 ! mocm 28: rbuf->size = 0;
! 29: rbuf->read_pos = 0;
! 30: rbuf->write_pos = 0;
1.1 cvs 31:
32: if (size > 0){
33: if( !(rbuf->buffy = (char *) vmalloc(sizeof(char)*size)) ){
1.3 mocm 34: MDEBUG(0,
1.1 cvs 35: "Not enough memory for ringbuffy\n");
36: return -1;
37: }
38: } else {
1.3 mocm 39: MDEBUG(0, "Wrong size for ringbuffy\n");
1.1 cvs 40: return -1;
41: }
42:
1.4 ! mocm 43: rbuf->size = size;
1.1 cvs 44: return 0;
45: }
46:
47:
48: void ring_destroy(ringbuffy *rbuf)
49: {
50: if (rbuf->size){
51: vfree(rbuf->buffy);
52: rbuf->buffy = NULL;
53: }
54: rbuf->size = 0;
55: rbuf->read_pos = 0;
56: rbuf->write_pos = 0;
57: }
58:
59:
60: int ring_write(ringbuffy *rbuf, const char *data, int count)
61: {
62:
63: long diff, free, pos, rest;
64:
65:
66: if (count <=0 || !rbuf->buffy) return 0;
67: pos = rbuf->write_pos;
68: rest = rbuf->size - pos;
69: diff = rbuf->read_pos - pos;
70: free = (diff > 0) ? diff-4 : rbuf->size+diff-4;
71:
72: if ( free <= 0 ) return 0;
73: if ( free < count ) count = free;
74:
75: if (count >= rest){
76: if(copy_from_user (rbuf->buffy+pos, data, rest))
77: return -EFAULT;
78: if (count - rest)
79: if(copy_from_user(rbuf->buffy, data+rest,
80: count - rest))
81: return -EFAULT;
82: rbuf->write_pos = count - rest;
83: } else {
84: copy_from_user (rbuf->buffy+pos, data, count);
85: rbuf->write_pos += count;
86: }
87:
88: return count;
89: }
90:
91:
1.2 mocm 92: int ring_writek(ringbuffy *rbuf, const char *data, int count)
93: {
94:
95: long diff, free, pos, rest;
96:
97:
98: if (count <=0 || !rbuf->buffy) return 0;
99: pos = rbuf->write_pos;
100: rest = rbuf->size - pos;
101: diff = rbuf->read_pos - pos;
102: free = (diff > 0) ? diff-4 : rbuf->size+diff-4;
103:
104: if ( free <= 0 ) return 0;
105: if ( free < count ) count = free;
106:
107: if (count >= rest){
108: if(memcpy(rbuf->buffy+pos, data, rest))
109: return -EFAULT;
110: if (count - rest)
111: if(memcpy(rbuf->buffy, data+rest,
112: count - rest))
113: return -EFAULT;
114: rbuf->write_pos = count - rest;
115: } else {
116: memcpy(rbuf->buffy+pos, data, count);
117: rbuf->write_pos += count;
118: }
119:
120: return count;
121: }
122:
123:
124:
1.1 cvs 125:
126: int ring_read(ringbuffy *rbuf, char *data, int count)
127: {
128:
129: long diff, free, pos, rest;
130:
131:
132: if (count <=0 || !rbuf->buffy) return 0;
133: pos = rbuf->read_pos;
134: rest = rbuf->size - pos;
135: diff = rbuf->write_pos - pos;
136: free = (diff >= 0) ? diff : rbuf->size+diff;
137:
138: if ( free <= 0 ) return 0;
139: if ( free < count ) count = free;
140:
141: if ( count >= rest ){
142: memcpy(data,rbuf->buffy+pos,rest);
143: if ( count - rest)
144: memcpy(data+rest,rbuf->buffy,count-rest);
145: rbuf->read_pos = count - rest;
146: } else {
147: memcpy(data,rbuf->buffy+pos,count);
148: rbuf->read_pos += count;
149: }
150:
151: return count;
152: }
153:
154: int ring_read_direct(ringbuffy *rbuf, int addr, int count)
155: {
156:
157: long diff, free, pos, rest;
158:
159:
160: if (count <=0 || !rbuf->buffy) return 0;
161: pos = rbuf->read_pos;
162: rest = rbuf->size - pos;
163: diff = rbuf->write_pos - pos;
164: free = (diff >= 0) ? diff : rbuf->size+diff;
165:
166: if ( free <= 0 ) return 0;
167: if ( free < count ) count = free;
168:
169: if ( count >= rest ){
170: outsl_ns(addr,rbuf->buffy+pos,rest/4);
171: if ( count - rest)
172: outsl_ns(addr,rbuf->buffy,(count-rest)/4);
173: rbuf->read_pos = count - rest;
174: } else {
175: outsl_ns(addr,rbuf->buffy+pos,count/4);
176: rbuf->read_pos += count;
177: }
178:
179: return count;
180: }
181:
182:
183: long ring_read_rest(ringbuffy *rbuf){
1.2 mocm 184: long diff, free, pos;
1.1 cvs 185:
186: if (!rbuf->buffy) return 0;
187: pos = rbuf->read_pos;
188: diff = rbuf->write_pos - pos;
189: free = (diff >= 0) ? diff : rbuf->size+diff;
190:
191: return free;
192: }
193:
194: long ring_write_rest(ringbuffy *rbuf){
1.2 mocm 195: long diff, free, pos;
1.1 cvs 196:
197: if (!rbuf->buffy) return 0;
198: pos = rbuf->write_pos;
199: diff = rbuf->read_pos - pos;
200: free = (diff > 0) ? diff-4 : rbuf->size+diff-4;
201:
202: return free;
203: }
204:
205: void ring_flush(ringbuffy *rbuf){
206: rbuf->read_pos = 0;
207: rbuf->write_pos = 0;
208: }
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