diff options
Diffstat (limited to 'src/fileio.cpp')
| -rw-r--r-- | src/fileio.cpp | 66 |
1 files changed, 63 insertions, 3 deletions
diff --git a/src/fileio.cpp b/src/fileio.cpp index 2a09916ea..e7e95453f 100644 --- a/src/fileio.cpp +++ b/src/fileio.cpp @@ -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 *filename) 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); } |