summaryrefslogtreecommitdiff
path: root/indra/llcommon/lllivefile.cpp
blob: ea485c2d86aab59f3dae9e502ac92b038f6ed999 (plain)
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
/** 
 * @file lllivefile.cpp
 *
 * $LicenseInfo:firstyear=2006&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "lllivefile.h"
#include "llframetimer.h"
#include "lleventtimer.h"

const F32 DEFAULT_CONFIG_FILE_REFRESH = 5.0f;


class LLLiveFile::Impl
{
public:
	Impl(const std::string& filename, const F32 refresh_period);
	~Impl();
	
	bool check();
	void changed();
	
	bool mForceCheck;
	F32 mRefreshPeriod;
	LLFrameTimer mRefreshTimer;

	std::string mFilename;
	time_t mLastModTime;
	time_t mLastStatTime;
	bool mLastExists;
	
	LLEventTimer* mEventTimer;
private:
    LOG_CLASS(LLLiveFile);
};

LLLiveFile::Impl::Impl(const std::string& filename, const F32 refresh_period)
	:
	mForceCheck(true),
	mRefreshPeriod(refresh_period),
	mFilename(filename),
	mLastModTime(0),
	mLastStatTime(0),
	mLastExists(false),
	mEventTimer(NULL)
{
}

LLLiveFile::Impl::~Impl()
{
	delete mEventTimer;
}

LLLiveFile::LLLiveFile(const std::string& filename, const F32 refresh_period)
	: impl(* new Impl(filename, refresh_period))
{
}

LLLiveFile::~LLLiveFile()
{
	delete &impl;
}


bool LLLiveFile::Impl::check()
{
    bool detected_change = false;
    // Skip the check if not enough time has elapsed and we're not
    // forcing a check of the file
	if (mForceCheck || mRefreshTimer.getElapsedTimeF32() >= mRefreshPeriod)
	{
        mForceCheck = false;   // force only forces one check
        mRefreshTimer.reset(); // don't check again until mRefreshPeriod has passed

        // Stat the file to see if it exists and when it was last modified.
        llstat stat_data;
        if (LLFile::stat(mFilename, &stat_data))
        {
            // Couldn't stat the file, that means it doesn't exist or is
            // broken somehow.  
            if (mLastExists)
            {
                mLastExists = false;
                detected_change = true;	// no longer existing is a change!
                LL_DEBUGS() << "detected deleted file '" << mFilename << "'" << LL_ENDL;
            }
        }
        else
        {
            // The file exists
            if ( ! mLastExists )
            {
                // last check, it did not exist - that counts as a change
                LL_DEBUGS() << "detected created file '" << mFilename << "'" << LL_ENDL;
                detected_change = true;
            }
            else if ( stat_data.st_mtime > mLastModTime )
            {
                // file modification time is newer than last check
                LL_DEBUGS() << "detected updated file '" << mFilename << "'" << LL_ENDL;
                detected_change = true;
            }
            mLastExists = true;
            mLastStatTime = stat_data.st_mtime;
        }
    }
    if (detected_change)
    {
        LL_INFOS() << "detected file change '" << mFilename << "'" << LL_ENDL;
    }
    return detected_change;
}

void LLLiveFile::Impl::changed()
{
	// we wanted to read this file, and we were successful.
	mLastModTime = mLastStatTime;
}

bool LLLiveFile::checkAndReload()
{
	bool changed = impl.check();
	if (changed)
	{
		if(loadFile())
		{
			impl.changed();
			this->changed();
		}
		else
		{
			changed = false;
		}
	}
	return changed;
}

std::string LLLiveFile::filename() const
{
	return impl.mFilename;
}

namespace
{
	class LiveFileEventTimer : public LLEventTimer
	{
	public:
		LiveFileEventTimer(LLLiveFile& f, F32 refresh)
			: LLEventTimer(refresh), mLiveFile(f)
			{ }
			
		BOOL tick()
		{ 
			mLiveFile.checkAndReload(); 
			return FALSE;
		}
	
	private:
		LLLiveFile& mLiveFile;
	};
	
}

void LLLiveFile::addToEventTimer()
{
	impl.mEventTimer = new LiveFileEventTimer(*this, impl.mRefreshPeriod);
}

void LLLiveFile::setRefreshPeriod(F32 seconds)
{
	if (seconds < 0.f)
	{
		seconds = -seconds;
	}
	impl.mRefreshPeriod = seconds;
}