1 files changed, 144 insertions, 0 deletions
diff --git a/legacystorage.c b/legacystorage.c
new file mode 100644
index 0000000..3bed512
--- /dev/null
+++ b/legacystorage.c
@@ -0,0 +1,144 @@
+/*************************************************************** -*- 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;
+}