cpp/openttd-patchpack/source Changeset - r5967:3569c8447441

Changeset - r5967:3569c8447441

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truelight - 17 years ago 2007-02-08 23:46:25
truelight@openttd.org

(svn r8647) -Codechange: add a general way to handle platforms who can only have a limited amount of file-descripters open at any given time.
The Fios keeps track how many times a file is opened, and tries to close up files which aren't used often.
The first platform using this is PSP. Patch based on the work of Turulo.

2 files changed with 70 insertions and 3 deletions:

src/fileio.cpp

src/stdafx.h

0 comments (0 inline, 0 general)

src/fileio.cpp

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@@ @@ -7,19 +7,26 @@ @@
 #include "string.h"
 #include "macros.h"
 #include "variables.h"
 #include "debug.h"
 /*************************************************/
 /* FILE IO ROUTINES ******************************/
 /*************************************************/
 #define FIO_BUFFER_SIZE 512
 #define MAX_HANDLES 64
 typedef struct {
 	byte *buffer, *buffer_end;          ///< position pointer in local buffer and last valid byte of buffer
 	uint32 pos;                         ///< current (system) position in file
 	FILE *cur_fh;                       ///< current file handle
-	FILE *handles[64];                  ///< array of file handles we can have open
+	FILE *handles[MAX_HANDLES];         ///< array of file handles we can have open
 	byte buffer_start[FIO_BUFFER_SIZE]; ///< local buffer when read from file
 #if defined(LIMITED_FDS)
 	uint open_handles;                  ///< current amount of open handles
 	const char *filename[MAX_HANDLES];  ///< array of filenames we (should) have open
 	uint usage_count[MAX_HANDLES];      ///< count how many times this file has been opened
 #endif /* LIMITED_FDS */
 } Fio;
 static Fio _fio;
@@ @@ -38,10 +45,27 @@ void FioSeekTo(uint32 pos, int mode) @@
 	fseek(_fio.cur_fh, _fio.pos, SEEK_SET);
+}
 #if defined(LIMITED_FDS)
 static void FioRestoreFile(int slot)
+{
 	/* Do we still have the file open, or should we reopen it? */
 	if (_fio.handles[slot] == NULL) {
 		DEBUG(misc, 6, "Restoring file '%s' in slot '%d' from disk", _fio.filename[slot], slot);
 		FioOpenFile(slot, _fio.filename[slot]);
+	}
 	_fio.usage_count[slot]++;
+}
 #endif /* LIMITED_FDS */
 // Seek to a file and a position
 void FioSeekToFile(uint32 pos)
+{
 	FILE *f = _fio.handles[pos >> 24];
 	FILE *f;
 #if defined(LIMITED_FDS)
 	/* Make sure we have this file open */
 	FioRestoreFile(pos >> 24);
 #endif /* LIMITED_FDS */
 	f = _fio.handles[pos >> 24];
 	assert(f != NULL);
 	_fio.cur_fh = f;
 	FioSeekTo(GB(pos, 0, 24), SEEK_SET);
@@ @@ -92,6 +116,9 @@ static inline void FioCloseFile(int slot @@
 	if (_fio.handles[slot] != NULL) {
 		fclose(_fio.handles[slot]);
 		_fio.handles[slot] = NULL;
 #if defined(LIMITED_FDS)
 		_fio.open_handles--;
 #endif /* LIMITED_FDS */
+	}
+}
@@ @@ -112,6 +139,30 @@ bool FioCheckFileExists(const char *file @@
 	return true;
+}
 #if defined(LIMITED_FDS)
 static void FioFreeHandle()
+{
 	/* If we are about to open a file that will exceed the limit, close a file */
 	if (_fio.open_handles + 1 == LIMITED_FDS) {
 		uint i, count;
 		int slot;
 		count = UINT_MAX;
 		slot = -1;
 		/* Find the file that is used the least */
 		for (i = 0; i < lengthof(_fio.handles); i++) {
 			if (_fio.handles[i] != NULL && _fio.usage_count[i] < count) {
 				count = _fio.usage_count[i];
 				slot  = i;
+			}
+		}
 		assert(slot != -1);
 		DEBUG(misc, 6, "Closing filehandler '%s' in slot '%d' because of fd-limit", _fio.filename[slot], slot);
 		FioCloseFile(slot);
+	}
+}
 #endif /* LIMITED_FDS */
 FILE *FioFOpenFile(const char *filename)
+{
 	FILE *f;
@@ @@ -141,11 +192,20 @@ FILE *FioFOpenFile(const char *filename) @@
 void FioOpenFile(int slot, const char *filename)
+{
-	FILE *f = FioFOpenFile(filename);
 	FILE *f;
 #if defined(LIMITED_FDS)
 	FioFreeHandle();
 #endif /* LIMITED_FDS */
 	f = FioFOpenFile(filename);
 	if (f == NULL) error("Cannot open file '%s%s'", _paths.data_dir, filename);
 	FioCloseFile(slot); // if file was opened before, close it
 	_fio.handles[slot] = f;
 #if defined(LIMITED_FDS)
 	_fio.filename[slot] = filename;
 	_fio.usage_count[slot] = 0;
 	_fio.open_handles++;
 #endif /* LIMITED_FDS */
 	FioSeekToFile(slot << 24);
+}

src/stdafx.h

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@@ @@ -77,6 +77,13 @@ @@
 # define BSWAP16(x) ((x) >> 8 | (x) << 8)
 #endif /* __APPLE__ */
 #if defined(PSP)
 /* PSP can only have 10 file-descriptors open at any given time, but this
  *  switch only limits reads via the Fio system. So keep 2 fds free for things
  *  like saving a game. */
 #define LIMITED_FDS 8
 #endif /* PSP */
 /* by default we use [] var arrays */
 #define VARARRAY_SIZE

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