File: buffer.c

package info (click to toggle)
luasocket 3.0~rc1+git+ac3201d-4
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 2,216 kB
  • sloc: ansic: 4,487; makefile: 320; sh: 116
file content (273 lines) | stat: -rw-r--r-- 10,464 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
/*=========================================================================*\
* Input/Output interface for Lua programs
* LuaSocket toolkit
\*=========================================================================*/
#include "lua.h"
#include "lauxlib.h"
#include "compat.h"

#include "buffer.h"

/*=========================================================================*\
* Internal function prototypes
\*=========================================================================*/
static int recvraw(p_buffer buf, size_t wanted, luaL_Buffer *b);
static int recvline(p_buffer buf, luaL_Buffer *b);
static int recvall(p_buffer buf, luaL_Buffer *b);
static int buffer_get(p_buffer buf, const char **data, size_t *count);
static void buffer_skip(p_buffer buf, size_t count);
static int sendraw(p_buffer buf, const char *data, size_t count, size_t *sent);

/* min and max macros */
#ifndef MIN
#define MIN(x, y) ((x) < (y) ? x : y)
#endif
#ifndef MAX
#define MAX(x, y) ((x) > (y) ? x : y)
#endif

/*=========================================================================*\
* Exported functions
\*=========================================================================*/
/*-------------------------------------------------------------------------*\
* Initializes module
\*-------------------------------------------------------------------------*/
int buffer_open(lua_State *L) {
    (void) L;
    return 0;
}

/*-------------------------------------------------------------------------*\
* Initializes C structure
\*-------------------------------------------------------------------------*/
LUASOCKET_API void buffer_init(p_buffer buf, p_io io, p_timeout tm) {
    buf->first = buf->last = 0;
    buf->io = io;
    buf->tm = tm;
    buf->received = buf->sent = 0;
    buf->birthday = timeout_gettime();
}

/*-------------------------------------------------------------------------*\
* object:getstats() interface
\*-------------------------------------------------------------------------*/
LUASOCKET_API int buffer_meth_getstats(lua_State *L, p_buffer buf) {
    lua_pushnumber(L, (lua_Number) buf->received);
    lua_pushnumber(L, (lua_Number) buf->sent);
    lua_pushnumber(L, timeout_gettime() - buf->birthday);
    return 3;
}

/*-------------------------------------------------------------------------*\
* object:setstats() interface
\*-------------------------------------------------------------------------*/
LUASOCKET_API int buffer_meth_setstats(lua_State *L, p_buffer buf) {
    buf->received = (long) luaL_optnumber(L, 2, (lua_Number) buf->received);
    buf->sent = (long) luaL_optnumber(L, 3, (lua_Number) buf->sent);
    if (lua_isnumber(L, 4)) buf->birthday = timeout_gettime() - lua_tonumber(L, 4);
    lua_pushnumber(L, 1);
    return 1;
}

/*-------------------------------------------------------------------------*\
* object:send() interface
\*-------------------------------------------------------------------------*/
LUASOCKET_API int buffer_meth_send(lua_State *L, p_buffer buf) {
    int top = lua_gettop(L);
    int err = IO_DONE;
    size_t size = 0, sent = 0;
    const char *data = luaL_checklstring(L, 2, &size);
    long start = (long) luaL_optnumber(L, 3, 1);
    long end = (long) luaL_optnumber(L, 4, -1);
    timeout_markstart(buf->tm);
    if (start < 0) start = (long) (size+start+1);
    if (end < 0) end = (long) (size+end+1);
    if (start < 1) start = (long) 1;
    if (end > (long) size) end = (long) size;
    if (start <= end) err = sendraw(buf, data+start-1, end-start+1, &sent);
    /* check if there was an error */
    if (err != IO_DONE) {
        lua_pushnil(L);
        lua_pushstring(L, buf->io->error(buf->io->ctx, err));
        lua_pushnumber(L, (lua_Number) (sent+start-1));
    } else {
        lua_pushnumber(L, (lua_Number) (sent+start-1));
        lua_pushnil(L);
        lua_pushnil(L);
    }
#ifdef LUASOCKET_DEBUG
    /* push time elapsed during operation as the last return value */
    lua_pushnumber(L, timeout_gettime() - timeout_getstart(buf->tm));
#endif
    return lua_gettop(L) - top;
}

/*-------------------------------------------------------------------------*\
* object:receive() interface
\*-------------------------------------------------------------------------*/
LUASOCKET_API int buffer_meth_receive(lua_State *L, p_buffer buf) {
    int err = IO_DONE, top = lua_gettop(L);
    luaL_Buffer b;
    size_t size;
    const char *part = luaL_optlstring(L, 3, "", &size);
    timeout_markstart(buf->tm);
    /* initialize buffer with optional extra prefix
     * (useful for concatenating previous partial results) */
    luaL_buffinit(L, &b);
    luaL_addlstring(&b, part, size);
    /* receive new patterns */
    if (!lua_isnumber(L, 2)) {
        const char *p= luaL_optstring(L, 2, "*l");
        if (p[0] == '*' && p[1] == 'l') err = recvline(buf, &b);
        else if (p[0] == '*' && p[1] == 'a') err = recvall(buf, &b);
        else luaL_argcheck(L, 0, 2, "invalid receive pattern");
    /* get a fixed number of bytes (minus what was already partially
     * received) */
    } else {
        double n = lua_tonumber(L, 2);
        size_t wanted = (size_t) n;
        luaL_argcheck(L, n >= 0, 2, "invalid receive pattern");
        if (size == 0 || wanted > size)
            err = recvraw(buf, wanted-size, &b);
    }
    /* check if there was an error */
    if (err != IO_DONE) {
        /* we can't push anyting in the stack before pushing the
         * contents of the buffer. this is the reason for the complication */
        luaL_pushresult(&b);
        lua_pushstring(L, buf->io->error(buf->io->ctx, err));
        lua_pushvalue(L, -2);
        lua_pushnil(L);
        lua_replace(L, -4);
    } else {
        luaL_pushresult(&b);
        lua_pushnil(L);
        lua_pushnil(L);
    }
#ifdef LUASOCKET_DEBUG
    /* push time elapsed during operation as the last return value */
    lua_pushnumber(L, timeout_gettime() - timeout_getstart(buf->tm));
#endif
    return lua_gettop(L) - top;
}

/*-------------------------------------------------------------------------*\
* Determines if there is any data in the read buffer
\*-------------------------------------------------------------------------*/
LUASOCKET_API int buffer_isempty(p_buffer buf) {
    return buf->first >= buf->last;
}

/*=========================================================================*\
* Internal functions
\*=========================================================================*/
/*-------------------------------------------------------------------------*\
* Sends a block of data (unbuffered)
\*-------------------------------------------------------------------------*/
#define STEPSIZE 8192
static int sendraw(p_buffer buf, const char *data, size_t count, size_t *sent) {
    p_io io = buf->io;
    p_timeout tm = buf->tm;
    size_t total = 0;
    int err = IO_DONE;
    while (total < count && err == IO_DONE) {
        size_t done = 0;
        size_t step = (count-total <= STEPSIZE)? count-total: STEPSIZE;
        err = io->send(io->ctx, data+total, step, &done, tm);
        total += done;
    }
    *sent = total;
    buf->sent += total;
    return err;
}

/*-------------------------------------------------------------------------*\
* Reads a fixed number of bytes (buffered)
\*-------------------------------------------------------------------------*/
static int recvraw(p_buffer buf, size_t wanted, luaL_Buffer *b) {
    int err = IO_DONE;
    size_t total = 0;
    while (err == IO_DONE) {
        size_t count; const char *data;
        err = buffer_get(buf, &data, &count);
        count = MIN(count, wanted - total);
        luaL_addlstring(b, data, count);
        buffer_skip(buf, count);
        total += count;
        if (total >= wanted) break;
    }
    return err;
}

/*-------------------------------------------------------------------------*\
* Reads everything until the connection is closed (buffered)
\*-------------------------------------------------------------------------*/
static int recvall(p_buffer buf, luaL_Buffer *b) {
    int err = IO_DONE;
    size_t total = 0;
    while (err == IO_DONE) {
        const char *data; size_t count;
        err = buffer_get(buf, &data, &count);
        total += count;
        luaL_addlstring(b, data, count);
        buffer_skip(buf, count);
    }
    if (err == IO_CLOSED) {
        if (total > 0) return IO_DONE;
        else return IO_CLOSED;
    } else return err;
}

/*-------------------------------------------------------------------------*\
* Reads a line terminated by a CR LF pair or just by a LF. The CR and LF
* are not returned by the function and are discarded from the buffer
\*-------------------------------------------------------------------------*/
static int recvline(p_buffer buf, luaL_Buffer *b) {
    int err = IO_DONE;
    while (err == IO_DONE) {
        size_t count, pos; const char *data;
        err = buffer_get(buf, &data, &count);
        pos = 0;
        while (pos < count && data[pos] != '\n') {
            /* we ignore all \r's */
            if (data[pos] != '\r') luaL_addchar(b, data[pos]);
            pos++;
        }
        if (pos < count) { /* found '\n' */
            buffer_skip(buf, pos+1); /* skip '\n' too */
            break; /* we are done */
        } else /* reached the end of the buffer */
            buffer_skip(buf, pos);
    }
    return err;
}

/*-------------------------------------------------------------------------*\
* Skips a given number of bytes from read buffer. No data is read from the
* transport layer
\*-------------------------------------------------------------------------*/
static void buffer_skip(p_buffer buf, size_t count) {
    buf->received += count;
    buf->first += count;
    if (buffer_isempty(buf))
        buf->first = buf->last = 0;
}

/*-------------------------------------------------------------------------*\
* Return any data available in buffer, or get more data from transport layer
* if buffer is empty
\*-------------------------------------------------------------------------*/
static int buffer_get(p_buffer buf, const char **data, size_t *count) {
    int err = IO_DONE;
    p_io io = buf->io;
    p_timeout tm = buf->tm;
    if (buffer_isempty(buf)) {
        size_t got;
        err = io->recv(io->ctx, buf->data, BUF_SIZE, &got, tm);
        buf->first = 0;
        buf->last = got;
    }
    *count = buf->last - buf->first;
    *data = buf->data + buf->first;
    return err;
}