src/timeout.c

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/*=========================================================================*\
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* LuaSocket 2.0.2
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* Copyright (C) 2004-2007 Diego Nehab
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*
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* Timeout management functions
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*
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* RCS ID: $Id: timeout.c,v 1.30 2005/10/07 04:40:59 diego Exp $
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\*=========================================================================*/
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#include <stdio.h>
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#ifdef _WIN32
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#include <windows.h>
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#else
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#include <time.h>
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#include <sys/time.h>
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#endif
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#include <lua.h>
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#include <lauxlib.h>
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#include "timeout.h"
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/* min and max macros */
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#ifndef MIN
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#define MIN(x, y) ((x) < (y) ? x : y)
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#endif
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#ifndef MAX
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#define MAX(x, y) ((x) > (y) ? x : y)
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#endif
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/*=========================================================================*\
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* Exported functions.
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\*=========================================================================*/
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/*-------------------------------------------------------------------------*\
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* Initialize structure
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\*-------------------------------------------------------------------------*/
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void timeout_init(p_timeout tm, double block, double total) {
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    tm->block = block;
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    tm->total = total;
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}
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/*-------------------------------------------------------------------------*\
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* Determines how much time we have left for the next system call,
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* if the previous call was successful
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* Input
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*   tm: timeout control structure
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* Returns
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*   the number of ms left or -1 if there is no time limit
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\*-------------------------------------------------------------------------*/
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double timeout_get(p_timeout tm) {
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    if (tm->block < 0.0 && tm->total < 0.0) {
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        return -1;
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    } else if (tm->block < 0.0) {
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        double t = tm->total - timeout_gettime() + tm->start;
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        return MAX(t, 0.0);
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    } else if (tm->total < 0.0) {
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        return tm->block;
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    } else {
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        double t = tm->total - timeout_gettime() + tm->start;
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        return MIN(tm->block, MAX(t, 0.0));
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    }
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}
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/*-------------------------------------------------------------------------*\
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* Returns time since start of operation
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* Input
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*   tm: timeout control structure
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* Returns
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*   start field of structure
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\*-------------------------------------------------------------------------*/
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double timeout_getstart(p_timeout tm) {
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    return tm->start;
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}
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/*-------------------------------------------------------------------------*\
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* Determines how much time we have left for the next system call,
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* if the previous call was a failure
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* Input
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*   tm: timeout control structure
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* Returns
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*   the number of ms left or -1 if there is no time limit
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\*-------------------------------------------------------------------------*/
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double timeout_getretry(p_timeout tm) {
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    if (tm->block < 0.0 && tm->total < 0.0) {
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        return -1;
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    } else if (tm->block < 0.0) {
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        double t = tm->total - timeout_gettime() + tm->start;
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        return MAX(t, 0.0);
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    } else if (tm->total < 0.0) {
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        double t = tm->block - timeout_gettime() + tm->start;
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        return MAX(t, 0.0);
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    } else {
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        double t = tm->total - timeout_gettime() + tm->start;
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        return MIN(tm->block, MAX(t, 0.0));
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    }
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}
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/*-------------------------------------------------------------------------*\
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* Marks the operation start time in structure
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* Input
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*   tm: timeout control structure
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\*-------------------------------------------------------------------------*/
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p_timeout timeout_markstart(p_timeout tm) {
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    tm->start = timeout_gettime();
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    return tm;
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}
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/*-------------------------------------------------------------------------*\
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* Gets time in s, relative to January 1, 1970 (UTC)
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* Returns
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*   time in s.
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\*-------------------------------------------------------------------------*/
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#ifdef _WIN32
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double timeout_gettime(void) {
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    FILETIME ft;
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    double t;
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    GetSystemTimeAsFileTime(&ft);
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    /* Windows file time (time since January 1, 1601 (UTC)) */
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    t  = ft.dwLowDateTime/1.0e7 + ft.dwHighDateTime*(4294967296.0/1.0e7);
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    /* convert to Unix Epoch time (time since January 1, 1970 (UTC)) */
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    return (t - 11644473600.0);
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}
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#else
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double timeout_gettime(void) {
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    struct timeval v;
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    gettimeofday(&v, (struct timezone *) NULL);
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    /* Unix Epoch time (time since January 1, 1970 (UTC)) */
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    return v.tv_sec + v.tv_usec/1.0e6;
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}
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#endif
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/*-------------------------------------------------------------------------*\
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* Sets timeout values for IO operations
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* Lua Input: base, time [, mode]
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*   time: time out value in seconds
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*   mode: "b" for block timeout, "t" for total timeout. (default: b)
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\*-------------------------------------------------------------------------*/
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int timeout_meth_settimeout(lua_State *L, p_timeout tm) {
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    double t = luaL_optnumber(L, 2, -1);
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    const char *mode = luaL_optstring(L, 3, "b");
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    switch (*mode) {
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        case 'b':
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            tm->block = t;
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            break;
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        case 'r': case 't':
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            tm->total = t;
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            break;
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        default:
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            luaL_argcheck(L, 0, 3, "invalid timeout mode");
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            break;
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    }
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    lua_pushnumber(L, 1);
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    return 1;
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}