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authorKlaus Schmidinger <vdr@tvdr.de>2005-10-31 13:14:26 +0100
committerKlaus Schmidinger <vdr@tvdr.de>2005-10-31 13:14:26 +0100
commit697261c981fa877b94661d310c07b216ca708f4f (patch)
treecd24930cf7529657301f8d886dc510bdc594c989 /tools.c
parent998e3bd2c7d19485d001f1531d93fda2e92edb03 (diff)
downloadvdr-697261c981fa877b94661d310c07b216ca708f4f.tar.gz
vdr-697261c981fa877b94661d310c07b216ca708f4f.tar.bz2
The new class cUnbufferedFile is used for the recording files to avoid thrashing the file system cache1.3.35
Diffstat (limited to 'tools.c')
-rw-r--r--tools.c125
1 files changed, 124 insertions, 1 deletions
diff --git a/tools.c b/tools.c
index dbd78c97..aa20e6ed 100644
--- a/tools.c
+++ b/tools.c
@@ -4,7 +4,7 @@
* See the main source file 'vdr.c' for copyright information and
* how to reach the author.
*
- * $Id: tools.c 1.99 2005/09/25 12:56:06 kls Exp $
+ * $Id: tools.c 1.100 2005/10/31 12:56:15 kls Exp $
*/
#include "tools.h"
@@ -836,6 +836,129 @@ bool cSafeFile::Close(void)
return result;
}
+// --- cUnbufferedFile -------------------------------------------------------
+
+#define READ_AHEAD MEGABYTE(2)
+#define WRITE_BUFFER MEGABYTE(10)
+
+cUnbufferedFile::cUnbufferedFile(void)
+{
+ fd = -1;
+}
+
+cUnbufferedFile::~cUnbufferedFile()
+{
+ Close();
+}
+
+int cUnbufferedFile::Open(const char *FileName, int Flags, mode_t Mode)
+{
+ Close();
+ fd = open(FileName, Flags, Mode);
+ begin = end = ahead = -1;
+ written = 0;
+ return fd;
+}
+
+int cUnbufferedFile::Close(void)
+{
+ if (fd >= 0) {
+ if (ahead > end)
+ end = ahead;
+ if (begin >= 0 && end > begin) {
+ //dsyslog("close buffer: %d (flush: %d bytes, %ld-%ld)", fd, written, begin, end);
+ if (written)
+ fdatasync(fd);
+ posix_fadvise(fd, begin, end - begin, POSIX_FADV_DONTNEED);
+ }
+ begin = end = ahead = -1;
+ written = 0;
+ }
+ int OldFd = fd;
+ fd = -1;
+ return close(OldFd);
+}
+
+off_t cUnbufferedFile::Seek(off_t Offset, int Whence)
+{
+ if (fd >= 0)
+ return lseek(fd, Offset, Whence);
+ return -1;
+}
+
+ssize_t cUnbufferedFile::Read(void *Data, size_t Size)
+{
+ if (fd >= 0) {
+ off_t pos = lseek(fd, 0, SEEK_CUR);
+ // jump forward - adjust end position
+ if (pos > end)
+ end = pos;
+ // after adjusting end - don't clear more than previously requested
+ if (end > ahead)
+ end = ahead;
+ // jump backward - drop read ahead of previous run
+ if (pos < begin)
+ end = ahead;
+ if (begin >= 0 && end > begin)
+ posix_fadvise(fd, begin - KILOBYTE(200), end - begin + KILOBYTE(200), POSIX_FADV_DONTNEED);//XXX macros/parameters???
+ begin = pos;
+ ssize_t bytesRead = safe_read(fd, Data, Size);
+ if (bytesRead > 0) {
+ pos += bytesRead;
+ end = pos;
+ // this seems to trigger a non blocking read - this
+ // may or may not have been finished when we will be called next time.
+ // If it is not finished we can't release the not yet filled buffers.
+ // So this is commented out till we find a better solution.
+ //posix_fadvise(fd, pos, READ_AHEAD, POSIX_FADV_WILLNEED);
+ ahead = pos + READ_AHEAD;
+ }
+ else
+ end = pos;
+ return bytesRead;
+ }
+ return -1;
+}
+
+ssize_t cUnbufferedFile::Write(const void *Data, size_t Size)
+{
+ if (fd >=0) {
+ off_t pos = lseek(fd, 0, SEEK_CUR);
+ ssize_t bytesWritten = safe_write(fd, Data, Size);
+ if (bytesWritten >= 0) {
+ written += bytesWritten;
+ if (begin >= 0) {
+ if (pos < begin)
+ begin = pos;
+ }
+ else
+ begin = pos;
+ if (pos + bytesWritten > end)
+ end = pos + bytesWritten;
+ if (written > WRITE_BUFFER) {
+ //dsyslog("flush buffer: %d (%d bytes, %ld-%ld)", fd, written, begin, end);
+ fdatasync(fd);
+ if (begin >= 0 && end > begin)
+ posix_fadvise(fd, begin, end - begin, POSIX_FADV_DONTNEED);
+ begin = end = -1;
+ written = 0;
+ }
+ }
+ return bytesWritten;
+ }
+ return -1;
+}
+
+cUnbufferedFile *cUnbufferedFile::Create(const char *FileName, int Flags, mode_t Mode)
+{
+ cUnbufferedFile *File = new cUnbufferedFile;
+ if (File->Open(FileName, Flags, Mode) < 0) {
+ delete File;
+ File = NULL;
+ }
+ return File;
+}
+
// --- cLockFile -------------------------------------------------------------
#define LOCKFILENAME ".lock-vdr"