luasocket/src/buffer.c
2022-03-18 12:23:09 +03:00

274 lines
10 KiB
C

/*=========================================================================*\
* Input/Output interface for Lua programs
* LuaSocket toolkit
\*=========================================================================*/
#include "luasocket.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
\*-------------------------------------------------------------------------*/
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
\*-------------------------------------------------------------------------*/
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
\*-------------------------------------------------------------------------*/
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
\*-------------------------------------------------------------------------*/
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
\*-------------------------------------------------------------------------*/
int buffer_meth_receive(lua_State *L, p_buffer buf) {
int err = IO_DONE, top;
luaL_Buffer b;
size_t size;
const char *part = luaL_optlstring(L, 3, "", &size);
timeout_markstart(buf->tm);
/* make sure we don't confuse buffer stuff with arguments */
lua_settop(L, 3);
top = lua_gettop(L);
/* 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
\*-------------------------------------------------------------------------*/
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;
}