File: legacystorage.c

package info (click to toggle)
vdr-plugin-osdteletext 0.9.7-2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster
  • size: 684 kB
  • sloc: ansic: 9,963; makefile: 59; sh: 14
file content (144 lines) | stat: -rw-r--r-- 4,983 bytes parent folder | download | duplicates (4)
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
/*************************************************************** -*- c++ -*-
 *       Copyright (c) 2003,2004 by Marcel Wiesweg                         *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include <sys/vfs.h>

#include "legacystorage.h"

LegacyStorage::LegacyStorage(int maxMB)
  : fsBlockSize(1), pageBytes(TELETEXT_PAGESIZE)
{
   initMaxStorage(maxMB);
}

LegacyStorage::~LegacyStorage() {
}

/*
static inline int FilesForMegabytes(double MB, int blocksize) {
   double pageBytes;
   if (TELETEXT_PAGESIZE<=blocksize)
      pageBytes=blocksize;
   else
      pageBytes=((TELETEXT_PAGESIZE/blocksize)+1)*blocksize;
   //reserve 10% for directories
   return (int)( (1024.0 * 1024.0 * (MB-MB*0.1)) / pageBytes );
}*/

int LegacyStorage::actualFileSize(int netFileSize) {
   if (netFileSize<=0)
      return 0;
   if (netFileSize<=fsBlockSize)
      return fsBlockSize;
   else
      return ((netFileSize/fsBlockSize)+1)*fsBlockSize;
}

//max==0 means unlimited, max==-1 means a reasonable default value shall be calculated
void LegacyStorage::initMaxStorage(int maxMB) {
   struct statfs fs;
   if (statfs(getRootDir(), &fs)!=0) {
      esyslog("OSD-Teletext: Error statfs'ing root directory \"%s\": %s, cache size uncontrolled", getRootDir(), strerror(errno));
      return;
   }
   fsBlockSize=fs.f_bsize;

   pageBytes=actualFileSize(TELETEXT_PAGESIZE);

   if (maxMB>=0) {
      if (maxMB<3) {
         esyslog("OSD-Teletext: Request to use at most %d MB for caching. This is not enough, using 3 MB", maxMB);
         maxMB=3;
      }
      maxBytes=MEGABYTE(maxMB);
   } else if (maxMB==-1) {
      //calculate a default value
      double blocksPerMeg = 1024.0 * 1024.0 / fs.f_bsize;
      double capacityMB=fs.f_blocks / blocksPerMeg;
      double freeMB=(fs.f_bavail / blocksPerMeg);
      if (capacityMB<=50 || freeMB<50) {
         //small (<=50MB) filesystems as root dir are assumed to be dedicated for use as a teletext cache
         //for others, the maximum default size is set to 50 MB
         maxBytes=MEGABYTE((int)freeMB);
         //maxPages= FilesForMegabytes(freeMB, fs.f_bsize);
         if (freeMB<3.0) {
            esyslog("OSD-Teletext: Less than %.1f MB free on filesystem of root directory \"%s\"!", freeMB, getRootDir());
            maxBytes=MEGABYTE(3);
         }
      } else {
         //the maximum default size is set to 50 MB
         maxBytes=MEGABYTE(50);
      }
      //printf("Set maxBytes to %ld, %.2f %.2f\n", maxBytes, capacityMB, freeMB);
   }
}

void LegacyStorage::cleanUp() {
   byteCount -= Storage::doCleanUp();
}

void LegacyStorage::registerFile(PageID page) {
   //pageBytes is already effective size
   if ( maxBytes && (byteCount+=pageBytes)>maxBytes )
      freeSpace();
}

StorageHandle LegacyStorage::openForReading(PageID page, bool countAsAccess) {
   //the countAsAccess argument was intended for use in a LRU cache, currently unused
   char filename[PATH_MAX];
   getFilename(filename, sizeof(filename), page);
   StorageHandle ret=(StorageHandle)open(filename, O_RDONLY);
   return ret;
}

StorageHandle LegacyStorage::openForWriting(PageID page) {
   static bool wroteError=false;
   char filename[PATH_MAX];
   getFilename(filename, sizeof(filename), page);
   bool existed=exists(filename);
   //first try
   StorageHandle fd=(StorageHandle)open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
   if (fd) {
      if (!existed)
         registerFile(page);
      return fd;
   }
   //no space on disk? make some space available
   if (errno == ENOSPC)
      freeSpace();
   //second try
   fd=(StorageHandle)open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
   if (!fd && !wroteError) {
      //report error to syslog - once!
      wroteError=true;
      esyslog("OSD-Teletext: Error opening teletext file %s: %s", filename, strerror(errno));
   }
   //make sure newly created files are counted
   if (fd && !existed)
      registerFile(page);
   return fd;
}

ssize_t LegacyStorage::write(const void *ptr, size_t size, StorageHandle stream) {
   ssize_t written;
   if (!(written=::write((int)stream, ptr, size)) ) {
      switch (errno) {
      case ENOSPC:
         freeSpace();
         return ::write((int)stream, ptr, size);
      case EINTR:
         esyslog("OSD-Teletext: EINTR while writing. Please contact the author and tell him this happened.");
         break;
      default:
         break;
      }
   }
   return written;
}