buffile.h File Reference

#include "storage/sharedfileset.h"

Include dependency graph for buffile.h:

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Typedefs
typedef struct BufFile	BufFile

Functions
BufFile *	BufFileCreateTemp (bool interXact)
void	BufFileClose (BufFile *file)
size_t	BufFileRead (BufFile *file, void *ptr, size_t size)
size_t	BufFileWrite (BufFile *file, void *ptr, size_t size)
int	BufFileSeek (BufFile *file, int fileno, off_t offset, int whence)
void	BufFileTell (BufFile *file, int *fileno, off_t *offset)
int	BufFileSeekBlock (BufFile *file, long blknum)
int64	BufFileSize (BufFile *file)
long	BufFileAppend (BufFile *target, BufFile *source)
BufFile *	BufFileCreateShared (SharedFileSet *fileset, const char *name)
void	BufFileExportShared (BufFile *file)
BufFile *	BufFileOpenShared (SharedFileSet *fileset, const char *name)
void	BufFileDeleteShared (SharedFileSet *fileset, const char *name)

Typedef Documentation

BufFile

typedef struct BufFile BufFile

Definition at line 33 of file buffile.h.

Function Documentation

BufFileAppend()

long BufFileAppend	(	BufFile *	target,
		BufFile *	source
	)

Definition at line 824 of file buffile.c.

References Assert, BUFFILE_SEG_SIZE, BufFile::dirty, elog, ERROR, BufFile::files, BufFile::fileset, i, BufFile::numFiles, BufFile::readOnly, repalloc(), and BufFile::resowner.

Referenced by ltsConcatWorkerTapes().

{
    long        startBlock = target->numFiles * BUFFILE_SEG_SIZE;
    int         newNumFiles = target->numFiles + source->numFiles;
    int         i;

    Assert(target->fileset != NULL);
    Assert(source->readOnly);
    Assert(!source->dirty);
    Assert(source->fileset != NULL);

    if (target->resowner != source->resowner)
        elog(ERROR, "could not append BufFile with non-matching resource owner");

    target->files = (File *)
        repalloc(target->files, sizeof(File) * newNumFiles);
    for (i = target->numFiles; i < newNumFiles; i++)
        target->files[i] = source->files[i - target->numFiles];
    target->numFiles = newNumFiles;

    return startBlock;
}

BufFileClose()

void BufFileClose

(

BufFile *

file

)

Definition at line 391 of file buffile.c.

References BufFileFlush(), FileClose(), BufFile::files, i, BufFile::numFiles, and pfree().

Referenced by ExecHashJoinNewBatch(), ExecHashTableDestroy(), gistFreeBuildBuffers(), LogicalTapeSetClose(), sts_end_parallel_scan(), sts_end_write(), sts_parallel_scan_next(), tuplestore_clear(), and tuplestore_end().

{
    int         i;

    /* flush any unwritten data */
    BufFileFlush(file);
    /* close and delete the underlying file(s) */
    for (i = 0; i < file->numFiles; i++)
        FileClose(file->files[i]);
    /* release the buffer space */
    pfree(file->files);
    pfree(file);
}

BufFileCreateShared()

BufFile* BufFileCreateShared	(	SharedFileSet *	fileset,
		const char *	name
	)

Definition at line 258 of file buffile.c.

References BufFile::files, BufFile::fileset, makeBufFileCommon(), MakeNewSharedSegment(), BufFile::name, palloc(), pstrdup(), and BufFile::readOnly.

Referenced by LogicalTapeSetCreate(), and sts_puttuple().

{
    BufFile    *file;

    file = makeBufFileCommon(1);
    file->fileset = fileset;
    file->name = pstrdup(name);
    file->files = (File *) palloc(sizeof(File));
    file->files[0] = MakeNewSharedSegment(file, 0);
    file->readOnly = false;

    return file;
}

BufFileCreateTemp()

BufFile* BufFileCreateTemp

(

bool

interXact

)

Definition at line 184 of file buffile.c.

References Assert, BufFile::isInterXact, makeBufFile(), OpenTemporaryFile(), and PrepareTempTablespaces().

Referenced by ExecHashJoinSaveTuple(), gistInitBuildBuffers(), LogicalTapeSetCreate(), and tuplestore_puttuple_common().

{
    BufFile    *file;
    File        pfile;

    /*
     * Ensure that temp tablespaces are set up for OpenTemporaryFile to use.
     * Possibly the caller will have done this already, but it seems useful to
     * double-check here.  Failure to do this at all would result in the temp
     * files always getting placed in the default tablespace, which is a
     * pretty hard-to-detect bug.  Callers may prefer to do it earlier if they
     * want to be sure that any required catalog access is done in some other
     * resource context.
     */
    PrepareTempTablespaces();

    pfile = OpenTemporaryFile(interXact);
    Assert(pfile >= 0);

    file = makeBufFile(pfile);
    file->isInterXact = interXact;

    return file;
}

BufFileDeleteShared()

void BufFileDeleteShared	(	SharedFileSet *	fileset,
		const char *	name
	)

Definition at line 343 of file buffile.c.

References CHECK_FOR_INTERRUPTS, elog, ERROR, MAXPGPATH, SharedFileSetDelete(), and SharedSegmentName().

{
    char        segment_name[MAXPGPATH];
    int         segment = 0;
    bool        found = false;

    /*
     * We don't know how many segments the file has.  We'll keep deleting
     * until we run out.  If we don't manage to find even an initial segment,
     * raise an error.
     */
    for (;;)
    {
        SharedSegmentName(segment_name, name, segment);
        if (!SharedFileSetDelete(fileset, segment_name, true))
            break;
        found = true;
        ++segment;

        CHECK_FOR_INTERRUPTS();
    }

    if (!found)
        elog(ERROR, "could not delete unknown shared BufFile \"%s\"", name);
}

BufFileExportShared()

void BufFileExportShared

(

BufFile *

file

)

Definition at line 373 of file buffile.c.

References Assert, BufFileFlush(), BufFile::fileset, and BufFile::readOnly.

Referenced by LogicalTapeFreeze().

{
    /* Must be a file belonging to a SharedFileSet. */
    Assert(file->fileset != NULL);

    /* It's probably a bug if someone calls this twice. */
    Assert(!file->readOnly);

    BufFileFlush(file);
    file->readOnly = true;
}

BufFileOpenShared()

BufFile* BufFileOpenShared	(	SharedFileSet *	fileset,
		const char *	name
	)

Definition at line 280 of file buffile.c.

References CHECK_FOR_INTERRUPTS, ereport, errcode_for_file_access(), errmsg(), ERROR, BufFile::files, BufFile::fileset, makeBufFileCommon(), MAXPGPATH, BufFile::name, palloc(), pstrdup(), BufFile::readOnly, repalloc(), SharedFileSetOpen(), and SharedSegmentName().

Referenced by ltsConcatWorkerTapes(), and sts_parallel_scan_next().

{
    BufFile    *file;
    char        segment_name[MAXPGPATH];
    Size        capacity = 16;
    File       *files;
    int         nfiles = 0;

    files = palloc(sizeof(File) * capacity);

    /*
     * We don't know how many segments there are, so we'll probe the
     * filesystem to find out.
     */
    for (;;)
    {
        /* See if we need to expand our file segment array. */
        if (nfiles + 1 > capacity)
        {
            capacity *= 2;
            files = repalloc(files, sizeof(File) * capacity);
        }
        /* Try to load a segment. */
        SharedSegmentName(segment_name, name, nfiles);
        files[nfiles] = SharedFileSetOpen(fileset, segment_name);
        if (files[nfiles] <= 0)
            break;
        ++nfiles;

        CHECK_FOR_INTERRUPTS();
    }

    /*
     * If we didn't find any files at all, then no BufFile exists with this
     * name.
     */
    if (nfiles == 0)
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not open temporary file \"%s\" from BufFile \"%s\": %m",
                        segment_name, name)));

    file = makeBufFileCommon(nfiles);
    file->files = files;
    file->readOnly = true;      /* Can't write to files opened this way */
    file->fileset = fileset;
    file->name = pstrdup(name);

    return file;
}

BufFileRead()

size_t BufFileRead	(	BufFile *	file,
		void *	ptr,
		size_t	size
	)

Definition at line 528 of file buffile.c.

References Assert, BufFile::buffer, BufFileFlush(), BufFileLoadBuffer(), BufFile::curOffset, PGAlignedBlock::data, BufFile::dirty, BufFile::nbytes, and BufFile::pos.

Referenced by ExecHashJoinGetSavedTuple(), getlen(), ltsReadBlock(), ReadTempFileBlock(), readtup_heap(), sts_parallel_scan_next(), and sts_read_tuple().

{
    size_t      nread = 0;
    size_t      nthistime;

    if (file->dirty)
    {
        if (BufFileFlush(file) != 0)
            return 0;           /* could not flush... */
        Assert(!file->dirty);
    }

    while (size > 0)
    {
        if (file->pos >= file->nbytes)
        {
            /* Try to load more data into buffer. */
            file->curOffset += file->pos;
            file->pos = 0;
            file->nbytes = 0;
            BufFileLoadBuffer(file);
            if (file->nbytes <= 0)
                break;          /* no more data available */
        }

        nthistime = file->nbytes - file->pos;
        if (nthistime > size)
            nthistime = size;
        Assert(nthistime > 0);

        memcpy(ptr, file->buffer.data + file->pos, nthistime);

        file->pos += nthistime;
        ptr = (void *) ((char *) ptr + nthistime);
        size -= nthistime;
        nread += nthistime;
    }

    return nread;
}

BufFileSeek()

int BufFileSeek	(	BufFile *	file,
		int	fileno,
		off_t	offset,
		int	whence
	)

Definition at line 650 of file buffile.c.

References BufFileFlush(), BufFile::curFile, BufFile::curOffset, elog, ERROR, MAX_PHYSICAL_FILESIZE, BufFile::nbytes, BufFile::numFiles, and BufFile::pos.

Referenced by BufFileSeekBlock(), ExecHashJoinNewBatch(), tuplestore_copy_read_pointer(), tuplestore_gettuple(), tuplestore_puttuple_common(), tuplestore_rescan(), and tuplestore_select_read_pointer().

{
    int         newFile;
    off_t       newOffset;

    switch (whence)
    {
        case SEEK_SET:
            if (fileno < 0)
                return EOF;
            newFile = fileno;
            newOffset = offset;
            break;
        case SEEK_CUR:

            /*
             * Relative seek considers only the signed offset, ignoring
             * fileno. Note that large offsets (> 1 GB) risk overflow in this
             * add, unless we have 64-bit off_t.
             */
            newFile = file->curFile;
            newOffset = (file->curOffset + file->pos) + offset;
            break;
#ifdef NOT_USED
        case SEEK_END:
            /* could be implemented, not needed currently */
            break;
#endif
        default:
            elog(ERROR, "invalid whence: %d", whence);
            return EOF;
    }
    while (newOffset < 0)
    {
        if (--newFile < 0)
            return EOF;
        newOffset += MAX_PHYSICAL_FILESIZE;
    }
    if (newFile == file->curFile &&
        newOffset >= file->curOffset &&
        newOffset <= file->curOffset + file->nbytes)
    {
        /*
         * Seek is to a point within existing buffer; we can just adjust
         * pos-within-buffer, without flushing buffer.  Note this is OK
         * whether reading or writing, but buffer remains dirty if we were
         * writing.
         */
        file->pos = (int) (newOffset - file->curOffset);
        return 0;
    }
    /* Otherwise, must reposition buffer, so flush any dirty data */
    if (BufFileFlush(file) != 0)
        return EOF;

    /*
     * At this point and no sooner, check for seek past last segment. The
     * above flush could have created a new segment, so checking sooner would
     * not work (at least not with this code).
     */

    /* convert seek to "start of next seg" to "end of last seg" */
    if (newFile == file->numFiles && newOffset == 0)
    {
        newFile--;
        newOffset = MAX_PHYSICAL_FILESIZE;
    }
    while (newOffset > MAX_PHYSICAL_FILESIZE)
    {
        if (++newFile >= file->numFiles)
            return EOF;
        newOffset -= MAX_PHYSICAL_FILESIZE;
    }
    if (newFile >= file->numFiles)
        return EOF;
    /* Seek is OK! */
    file->curFile = newFile;
    file->curOffset = newOffset;
    file->pos = 0;
    file->nbytes = 0;
    return 0;
}

BufFileSeekBlock()

int BufFileSeekBlock	(	BufFile *	file,
		long	blknum
	)

Definition at line 752 of file buffile.c.

References BUFFILE_SEG_SIZE, BufFileSeek(), BufFile::curFile, BufFile::curOffset, and BufFile::pos.

Referenced by ltsReadBlock(), ltsWriteBlock(), ReadTempFileBlock(), sts_parallel_scan_next(), and WriteTempFileBlock().

{
    return BufFileSeek(file,
                       (int) (blknum / BUFFILE_SEG_SIZE),
                       (off_t) (blknum % BUFFILE_SEG_SIZE) * BLCKSZ,
                       SEEK_SET);
}

BufFileSize()

int64 BufFileSize

(

BufFile *

file

)

Definition at line 785 of file buffile.c.

References Assert, ereport, errcode_for_file_access(), errmsg(), ERROR, FilePathName(), BufFile::files, BufFile::fileset, FileSize(), MAX_PHYSICAL_FILESIZE, BufFile::name, and BufFile::numFiles.

Referenced by ltsConcatWorkerTapes().

{
    int64       lastFileSize;

    Assert(file->fileset != NULL);

    /* Get the size of the last physical file. */
    lastFileSize = FileSize(file->files[file->numFiles - 1]);
    if (lastFileSize < 0)
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not determine size of temporary file \"%s\" from BufFile \"%s\": %m",
                        FilePathName(file->files[file->numFiles - 1]),
                        file->name)));

    return ((file->numFiles - 1) * (int64) MAX_PHYSICAL_FILESIZE) +
        lastFileSize;
}

BufFileTell()

void BufFileTell	(	BufFile *	file,
		int *	fileno,
		off_t *	offset
	)

Definition at line 734 of file buffile.c.

References BufFile::curFile, BufFile::curOffset, and BufFile::pos.

Referenced by dumptuples(), tuplestore_copy_read_pointer(), tuplestore_gettuple(), tuplestore_puttuple_common(), and tuplestore_select_read_pointer().

{
    *fileno = file->curFile;
    *offset = file->curOffset + file->pos;
}

BufFileWrite()

size_t BufFileWrite	(	BufFile *	file,
		void *	ptr,
		size_t	size
	)

Definition at line 575 of file buffile.c.

References Assert, BufFile::buffer, BufFileDumpBuffer(), BufFile::curOffset, PGAlignedBlock::data, BufFile::dirty, BufFile::nbytes, BufFile::pos, and BufFile::readOnly.

Referenced by ExecHashJoinSaveTuple(), ltsWriteBlock(), sts_flush_chunk(), WriteTempFileBlock(), and writetup_heap().

{
    size_t      nwritten = 0;
    size_t      nthistime;

    Assert(!file->readOnly);

    while (size > 0)
    {
        if (file->pos >= BLCKSZ)
        {
            /* Buffer full, dump it out */
            if (file->dirty)
            {
                BufFileDumpBuffer(file);
                if (file->dirty)
                    break;      /* I/O error */
            }
            else
            {
                /* Hmm, went directly from reading to writing? */
                file->curOffset += file->pos;
                file->pos = 0;
                file->nbytes = 0;
            }
        }

        nthistime = BLCKSZ - file->pos;
        if (nthistime > size)
            nthistime = size;
        Assert(nthistime > 0);

        memcpy(file->buffer.data + file->pos, ptr, nthistime);

        file->dirty = true;
        file->pos += nthistime;
        if (file->nbytes < file->pos)
            file->nbytes = file->pos;
        ptr = (void *) ((char *) ptr + nthistime);
        size -= nthistime;
        nwritten += nthistime;
    }

    return nwritten;
}