buffile.c File Reference

#include "postgres.h"
#include "commands/tablespace.h"
#include "executor/instrument.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "storage/buf_internals.h"
#include "storage/buffile.h"
#include "storage/fd.h"
#include "utils/resowner.h"

Include dependency graph for buffile.c:

Go to the source code of this file.

Data Structures
struct	BufFile

Macros
#define	MAX_PHYSICAL_FILESIZE   0x40000000
#define	BUFFILE_SEG_SIZE   (MAX_PHYSICAL_FILESIZE / BLCKSZ)

Functions
static BufFile *	makeBufFileCommon (int nfiles)
static BufFile *	makeBufFile (File firstfile)
static void	extendBufFile (BufFile *file)
static void	BufFileLoadBuffer (BufFile *file)
static void	BufFileDumpBuffer (BufFile *file)
static void	BufFileFlush (BufFile *file)
static File	MakeNewFileSetSegment (BufFile *buffile, int segment)
BufFile *	BufFileCreateTemp (bool interXact)
static void	FileSetSegmentName (char *name, const char *buffile_name, int segment)
BufFile *	BufFileCreateFileSet (FileSet *fileset, const char *name)
BufFile *	BufFileOpenFileSet (FileSet *fileset, const char *name, int mode, bool missing_ok)
void	BufFileDeleteFileSet (FileSet *fileset, const char *name, bool missing_ok)
void	BufFileExportFileSet (BufFile *file)
void	BufFileClose (BufFile *file)
static size_t	BufFileReadCommon (BufFile *file, void *ptr, size_t size, bool exact, bool eofOK)
size_t	BufFileRead (BufFile *file, void *ptr, size_t size)
void	BufFileReadExact (BufFile *file, void *ptr, size_t size)
size_t	BufFileReadMaybeEOF (BufFile *file, void *ptr, size_t size, bool eofOK)
void	BufFileWrite (BufFile *file, const 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)
void	BufFileTruncateFileSet (BufFile *file, int fileno, off_t offset)

Macro Definition Documentation

BUFFILE_SEG_SIZE

#define BUFFILE_SEG_SIZE   (MAX_PHYSICAL_FILESIZE / BLCKSZ)

Definition at line 63 of file buffile.c.

MAX_PHYSICAL_FILESIZE

#define MAX_PHYSICAL_FILESIZE   0x40000000

Definition at line 62 of file buffile.c.

Function Documentation

BufFileAppend()

long BufFileAppend	(	BufFile *	target,
		BufFile *	source
	)

Definition at line 920 of file buffile.c.

{
    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;
}

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

Referenced by LogicalTapeImport().

BufFileClose()

void BufFileClose

(

BufFile *

file

)

Definition at line 407 of file buffile.c.

{
    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);
}

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

Referenced by ensure_last_message(), ExecHashJoinNewBatch(), ExecHashTableDestroy(), gistFreeBuildBuffers(), LogicalTapeSetClose(), SendBackupManifest(), stream_abort_internal(), stream_close_file(), sts_end_parallel_scan(), sts_end_write(), sts_parallel_scan_next(), subxact_info_read(), subxact_info_write(), tuplestore_clear(), and tuplestore_end().

BufFileCreateFileSet()

BufFile* BufFileCreateFileSet	(	FileSet *	fileset,
		const char *	name
	)

Definition at line 262 of file buffile.c.

{
    BufFile    *file;
 
    file = makeBufFileCommon(1);
    file->fileset = fileset;
    file->name = pstrdup(name);
    file->files = (File *) palloc(sizeof(File));
    file->files[0] = MakeNewFileSetSegment(file, 0);
    file->readOnly = false;
 
    return file;
}

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

Referenced by LogicalTapeSetCreate(), stream_open_file(), sts_puttuple(), and subxact_info_write().

BufFileCreateTemp()

BufFile* BufFileCreateTemp

(

bool

interXact

)

Definition at line 188 of file buffile.c.

{
    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;
}

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

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

BufFileDeleteFileSet()

void BufFileDeleteFileSet	(	FileSet *	fileset,
		const char *	name,
		bool	missing_ok
	)

Definition at line 359 of file buffile.c.

{
    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 (;;)
    {
        FileSetSegmentName(segment_name, name, segment);
        if (!FileSetDelete(fileset, segment_name, true))
            break;
        found = true;
        ++segment;
 
        CHECK_FOR_INTERRUPTS();
    }
 
    if (!found && !missing_ok)
        elog(ERROR, "could not delete unknown BufFile \"%s\"", name);
}

References CHECK_FOR_INTERRUPTS, elog(), ERROR, FileSetDelete(), FileSetSegmentName(), MAXPGPATH, and name.

Referenced by stream_cleanup_files(), and subxact_info_write().

BufFileDumpBuffer()

static void BufFileDumpBuffer ( BufFile *  file )

static

Definition at line 490 of file buffile.c.

{
    int         wpos = 0;
    int         bytestowrite;
    File        thisfile;
 
    /*
     * Unlike BufFileLoadBuffer, we must dump the whole buffer even if it
     * crosses a component-file boundary; so we need a loop.
     */
    while (wpos < file->nbytes)
    {
        off_t       availbytes;
        instr_time  io_start;
        instr_time  io_time;
 
        /*
         * Advance to next component file if necessary and possible.
         */
        if (file->curOffset >= MAX_PHYSICAL_FILESIZE)
        {
            while (file->curFile + 1 >= file->numFiles)
                extendBufFile(file);
            file->curFile++;
            file->curOffset = 0L;
        }
 
        /*
         * Determine how much we need to write into this file.
         */
        bytestowrite = file->nbytes - wpos;
        availbytes = MAX_PHYSICAL_FILESIZE - file->curOffset;
 
        if ((off_t) bytestowrite > availbytes)
            bytestowrite = (int) availbytes;
 
        thisfile = file->files[file->curFile];
 
        if (track_io_timing)
            INSTR_TIME_SET_CURRENT(io_start);
        else
            INSTR_TIME_SET_ZERO(io_start);
 
        bytestowrite = FileWrite(thisfile,
                                 file->buffer.data + wpos,
                                 bytestowrite,
                                 file->curOffset,
                                 WAIT_EVENT_BUFFILE_WRITE);
        if (bytestowrite <= 0)
            ereport(ERROR,
                    (errcode_for_file_access(),
                     errmsg("could not write to file \"%s\": %m",
                            FilePathName(thisfile))));
 
        if (track_io_timing)
        {
            INSTR_TIME_SET_CURRENT(io_time);
            INSTR_TIME_SUBTRACT(io_time, io_start);
            INSTR_TIME_ADD(pgBufferUsage.temp_blk_write_time, io_time);
        }
 
        file->curOffset += bytestowrite;
        wpos += bytestowrite;
 
        pgBufferUsage.temp_blks_written++;
    }
    file->dirty = false;
 
    /*
     * At this point, curOffset has been advanced to the end of the buffer,
     * ie, its original value + nbytes.  We need to make it point to the
     * logical file position, ie, original value + pos, in case that is less
     * (as could happen due to a small backwards seek in a dirty buffer!)
     */
    file->curOffset -= (file->nbytes - file->pos);
    if (file->curOffset < 0)    /* handle possible segment crossing */
    {
        file->curFile--;
        Assert(file->curFile >= 0);
        file->curOffset += MAX_PHYSICAL_FILESIZE;
    }
 
    /*
     * Now we can set the buffer empty without changing the logical position
     */
    file->pos = 0;
    file->nbytes = 0;
}

References Assert(), BufFile::buffer, BufFile::curFile, BufFile::curOffset, PGAlignedBlock::data, BufFile::dirty, ereport, errcode_for_file_access(), errmsg(), ERROR, extendBufFile(), FilePathName(), BufFile::files, FileWrite(), INSTR_TIME_ADD, INSTR_TIME_SET_CURRENT, INSTR_TIME_SET_ZERO, INSTR_TIME_SUBTRACT, MAX_PHYSICAL_FILESIZE, BufFile::nbytes, BufFile::numFiles, pgBufferUsage, BufFile::pos, BufferUsage::temp_blk_write_time, BufferUsage::temp_blks_written, track_io_timing, WAIT_EVENT_BUFFILE_WRITE, and wpos.

Referenced by BufFileFlush(), and BufFileWrite().

BufFileExportFileSet()

void BufFileExportFileSet

(

BufFile *

file

)

Definition at line 389 of file buffile.c.

{
    /* Must be a file belonging to a FileSet. */
    Assert(file->fileset != NULL);
 
    /* It's probably a bug if someone calls this twice. */
    Assert(!file->readOnly);
 
    BufFileFlush(file);
    file->readOnly = true;
}

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

Referenced by LogicalTapeFreeze().

BufFileFlush()

static void BufFileFlush ( BufFile *  file )

static

Definition at line 717 of file buffile.c.

{
    if (file->dirty)
        BufFileDumpBuffer(file);
 
    Assert(!file->dirty);
}

References Assert(), BufFileDumpBuffer(), and BufFile::dirty.

Referenced by BufFileClose(), BufFileExportFileSet(), BufFileReadCommon(), and BufFileSeek().

BufFileLoadBuffer()

static void BufFileLoadBuffer ( BufFile *  file )

static

Definition at line 429 of file buffile.c.

{
    File        thisfile;
    instr_time  io_start;
    instr_time  io_time;
 
    /*
     * Advance to next component file if necessary and possible.
     */
    if (file->curOffset >= MAX_PHYSICAL_FILESIZE &&
        file->curFile + 1 < file->numFiles)
    {
        file->curFile++;
        file->curOffset = 0L;
    }
 
    thisfile = file->files[file->curFile];
 
    if (track_io_timing)
        INSTR_TIME_SET_CURRENT(io_start);
    else
        INSTR_TIME_SET_ZERO(io_start);
 
    /*
     * Read whatever we can get, up to a full bufferload.
     */
    file->nbytes = FileRead(thisfile,
                            file->buffer.data,
                            sizeof(file->buffer),
                            file->curOffset,
                            WAIT_EVENT_BUFFILE_READ);
    if (file->nbytes < 0)
    {
        file->nbytes = 0;
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not read file \"%s\": %m",
                        FilePathName(thisfile))));
    }
 
    if (track_io_timing)
    {
        INSTR_TIME_SET_CURRENT(io_time);
        INSTR_TIME_SUBTRACT(io_time, io_start);
        INSTR_TIME_ADD(pgBufferUsage.temp_blk_read_time, io_time);
    }
 
    /* we choose not to advance curOffset here */
 
    if (file->nbytes > 0)
        pgBufferUsage.temp_blks_read++;
}

References BufFile::buffer, BufFile::curFile, BufFile::curOffset, PGAlignedBlock::data, ereport, errcode_for_file_access(), errmsg(), ERROR, FilePathName(), FileRead(), BufFile::files, INSTR_TIME_ADD, INSTR_TIME_SET_CURRENT, INSTR_TIME_SET_ZERO, INSTR_TIME_SUBTRACT, MAX_PHYSICAL_FILESIZE, BufFile::nbytes, BufFile::numFiles, pgBufferUsage, BufferUsage::temp_blk_read_time, BufferUsage::temp_blks_read, track_io_timing, and WAIT_EVENT_BUFFILE_READ.

Referenced by BufFileReadCommon().

BufFileOpenFileSet()

BufFile* BufFileOpenFileSet	(	FileSet *	fileset,
		const char *	name,
		int	mode,
		bool	missing_ok
	)

Definition at line 286 of file buffile.c.

{
    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. */
        FileSetSegmentName(segment_name, name, nfiles);
        files[nfiles] = FileSetOpen(fileset, segment_name, mode);
        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)
    {
        /* free the memory */
        pfree(files);
 
        if (missing_ok)
            return NULL;
 
        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 = (mode == O_RDONLY);
    file->fileset = fileset;
    file->name = pstrdup(name);
 
    return file;
}

References CHECK_FOR_INTERRUPTS, ereport, errcode_for_file_access(), errmsg(), ERROR, BufFile::files, BufFile::fileset, FileSetOpen(), FileSetSegmentName(), makeBufFileCommon(), MAXPGPATH, mode, BufFile::name, name, palloc(), pfree(), pstrdup(), BufFile::readOnly, and repalloc().

Referenced by apply_spooled_messages(), ensure_last_message(), LogicalTapeImport(), stream_abort_internal(), stream_open_file(), sts_parallel_scan_next(), subxact_info_read(), and subxact_info_write().

BufFileRead()

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

Definition at line 642 of file buffile.c.

{
    return BufFileReadCommon(file, ptr, size, false, false);
}

References BufFileReadCommon().

BufFileReadCommon()

static size_t BufFileReadCommon ( BufFile *  file, void *  ptr, size_t  size, bool  exact, bool  eofOK  )

static

Definition at line 590 of file buffile.c.

{
    size_t      start_size = size;
    size_t      nread = 0;
    size_t      nthistime;
 
    BufFileFlush(file);
 
    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 = (char *) ptr + nthistime;
        size -= nthistime;
        nread += nthistime;
    }
 
    if (exact &&
        (nread != start_size && !(nread == 0 && eofOK)))
        ereport(ERROR,
                errcode_for_file_access(),
                file->name ?
                errmsg("could not read from file set \"%s\": read only %zu of %zu bytes",
                       file->name, nread, start_size) :
                errmsg("could not read from temporary file: read only %zu of %zu bytes",
                       nread, start_size));
 
    return nread;
}

References Assert(), BufFile::buffer, BufFileFlush(), BufFileLoadBuffer(), BufFile::curOffset, PGAlignedBlock::data, ereport, errcode_for_file_access(), errmsg(), ERROR, BufFile::name, BufFile::nbytes, and BufFile::pos.

Referenced by BufFileRead(), BufFileReadExact(), and BufFileReadMaybeEOF().

BufFileReadExact()

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

Definition at line 651 of file buffile.c.

{
    BufFileReadCommon(file, ptr, size, true, false);
}

References BufFileReadCommon().

Referenced by apply_spooled_messages(), ExecHashJoinGetSavedTuple(), ltsReadBlock(), ReadTempFileBlock(), readtup_heap(), SendBackupManifest(), sts_parallel_scan_next(), sts_read_tuple(), and subxact_info_read().

BufFileReadMaybeEOF()

size_t BufFileReadMaybeEOF	(	BufFile *	file,
		void *	ptr,
		size_t	size,
		bool	eofOK
	)

Definition at line 661 of file buffile.c.

{
    return BufFileReadCommon(file, ptr, size, true, eofOK);
}

References BufFileReadCommon().

Referenced by apply_spooled_messages(), ExecHashJoinGetSavedTuple(), and getlen().

BufFileSeek()

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

Definition at line 737 of file buffile.c.

{
    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;
        case SEEK_END:
 
            /*
             * The file size of the last file gives us the end offset of that
             * file.
             */
            newFile = file->numFiles - 1;
            newOffset = FileSize(file->files[file->numFiles - 1]);
            if (newOffset < 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)));
            break;
        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 */
    BufFileFlush(file);
 
    /*
     * 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;
}

References BufFileFlush(), BufFile::curFile, BufFile::curOffset, elog(), ereport, errcode_for_file_access(), errmsg(), ERROR, FilePathName(), BufFile::files, FileSize(), MAX_PHYSICAL_FILESIZE, BufFile::name, BufFile::nbytes, BufFile::numFiles, and BufFile::pos.

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

BufFileSeekBlock()

int BufFileSeekBlock	(	BufFile *	file,
		long	blknum
	)

Definition at line 848 of file buffile.c.

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

References BUFFILE_SEG_SIZE, and BufFileSeek().

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

BufFileSize()

int64 BufFileSize

(

BufFile *

file

)

Definition at line 881 of file buffile.c.

{
    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;
}

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 LogicalTapeImport().

BufFileTell()

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

Definition at line 830 of file buffile.c.

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

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

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

BufFileTruncateFileSet()

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

Definition at line 948 of file buffile.c.

{
    int         numFiles = file->numFiles;
    int         newFile = fileno;
    off_t       newOffset = file->curOffset;
    char        segment_name[MAXPGPATH];
    int         i;
 
    /*
     * Loop over all the files up to the given fileno and remove the files
     * that are greater than the fileno and truncate the given file up to the
     * offset. Note that we also remove the given fileno if the offset is 0
     * provided it is not the first file in which we truncate it.
     */
    for (i = file->numFiles - 1; i >= fileno; i--)
    {
        if ((i != fileno || offset == 0) && i != 0)
        {
            FileSetSegmentName(segment_name, file->name, i);
            FileClose(file->files[i]);
            if (!FileSetDelete(file->fileset, segment_name, true))
                ereport(ERROR,
                        (errcode_for_file_access(),
                         errmsg("could not delete fileset \"%s\": %m",
                                segment_name)));
            numFiles--;
            newOffset = MAX_PHYSICAL_FILESIZE;
 
            /*
             * This is required to indicate that we have deleted the given
             * fileno.
             */
            if (i == fileno)
                newFile--;
        }
        else
        {
            if (FileTruncate(file->files[i], offset,
                             WAIT_EVENT_BUFFILE_TRUNCATE) < 0)
                ereport(ERROR,
                        (errcode_for_file_access(),
                         errmsg("could not truncate file \"%s\": %m",
                                FilePathName(file->files[i]))));
            newOffset = offset;
        }
    }
 
    file->numFiles = numFiles;
 
    /*
     * If the truncate point is within existing buffer then we can just adjust
     * pos within buffer.
     */
    if (newFile == file->curFile &&
        newOffset >= file->curOffset &&
        newOffset <= file->curOffset + file->nbytes)
    {
        /* No need to reset the current pos if the new pos is greater. */
        if (newOffset <= file->curOffset + file->pos)
            file->pos = (int) (newOffset - file->curOffset);
 
        /* Adjust the nbytes for the current buffer. */
        file->nbytes = (int) (newOffset - file->curOffset);
    }
    else if (newFile == file->curFile &&
             newOffset < file->curOffset)
    {
        /*
         * The truncate point is within the existing file but prior to the
         * current position, so we can forget the current buffer and reset the
         * current position.
         */
        file->curOffset = newOffset;
        file->pos = 0;
        file->nbytes = 0;
    }
    else if (newFile < file->curFile)
    {
        /*
         * The truncate point is prior to the current file, so need to reset
         * the current position accordingly.
         */
        file->curFile = newFile;
        file->curOffset = newOffset;
        file->pos = 0;
        file->nbytes = 0;
    }
    /* Nothing to do, if the truncate point is beyond current file. */
}

References BufFile::curFile, BufFile::curOffset, ereport, errcode_for_file_access(), errmsg(), ERROR, FileClose(), FilePathName(), BufFile::files, BufFile::fileset, FileSetDelete(), FileSetSegmentName(), FileTruncate(), i, MAX_PHYSICAL_FILESIZE, MAXPGPATH, BufFile::name, BufFile::nbytes, BufFile::numFiles, BufFile::pos, and WAIT_EVENT_BUFFILE_TRUNCATE.

Referenced by stream_abort_internal().

BufFileWrite()

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

Definition at line 673 of file buffile.c.

{
    size_t      nthistime;
 
    Assert(!file->readOnly);
 
    while (size > 0)
    {
        if (file->pos >= BLCKSZ)
        {
            /* Buffer full, dump it out */
            if (file->dirty)
                BufFileDumpBuffer(file);
            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 = (const char *) ptr + nthistime;
        size -= nthistime;
    }
}

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

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

extendBufFile()

static void extendBufFile ( BufFile *  file )

static

Definition at line 151 of file buffile.c.

{
    File        pfile;
    ResourceOwner oldowner;
 
    /* Be sure to associate the file with the BufFile's resource owner */
    oldowner = CurrentResourceOwner;
    CurrentResourceOwner = file->resowner;
 
    if (file->fileset == NULL)
        pfile = OpenTemporaryFile(file->isInterXact);
    else
        pfile = MakeNewFileSetSegment(file, file->numFiles);
 
    Assert(pfile >= 0);
 
    CurrentResourceOwner = oldowner;
 
    file->files = (File *) repalloc(file->files,
                                    (file->numFiles + 1) * sizeof(File));
    file->files[file->numFiles] = pfile;
    file->numFiles++;
}

References Assert(), CurrentResourceOwner, BufFile::files, BufFile::fileset, BufFile::isInterXact, MakeNewFileSetSegment(), BufFile::numFiles, OpenTemporaryFile(), repalloc(), and BufFile::resowner.

Referenced by BufFileDumpBuffer().

FileSetSegmentName()

static void FileSetSegmentName ( char *  name, const char *  buffile_name, int  segment  )

static

Definition at line 217 of file buffile.c.

{
    snprintf(name, MAXPGPATH, "%s.%d", buffile_name, segment);
}

References MAXPGPATH, name, and snprintf.

Referenced by BufFileDeleteFileSet(), BufFileOpenFileSet(), BufFileTruncateFileSet(), and MakeNewFileSetSegment().

makeBufFile()

static BufFile * makeBufFile ( File  firstfile )

static

Definition at line 134 of file buffile.c.

{
    BufFile    *file = makeBufFileCommon(1);
 
    file->files = (File *) palloc(sizeof(File));
    file->files[0] = firstfile;
    file->readOnly = false;
    file->fileset = NULL;
    file->name = NULL;
 
    return file;
}

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

Referenced by BufFileCreateTemp().

makeBufFileCommon()

static BufFile * makeBufFileCommon ( int  nfiles )

static

Definition at line 113 of file buffile.c.

{
    BufFile    *file = (BufFile *) palloc(sizeof(BufFile));
 
    file->numFiles = nfiles;
    file->isInterXact = false;
    file->dirty = false;
    file->resowner = CurrentResourceOwner;
    file->curFile = 0;
    file->curOffset = 0L;
    file->pos = 0;
    file->nbytes = 0;
 
    return file;
}

References BufFile::curFile, BufFile::curOffset, CurrentResourceOwner, BufFile::dirty, BufFile::isInterXact, BufFile::nbytes, BufFile::numFiles, palloc(), BufFile::pos, and BufFile::resowner.

Referenced by BufFileCreateFileSet(), BufFileOpenFileSet(), and makeBufFile().

MakeNewFileSetSegment()

static File MakeNewFileSetSegment ( BufFile *  buffile, int  segment  )

static

Definition at line 226 of file buffile.c.

{
    char        name[MAXPGPATH];
    File        file;
 
    /*
     * It is possible that there are files left over from before a crash
     * restart with the same name.  In order for BufFileOpenFileSet() not to
     * get confused about how many segments there are, we'll unlink the next
     * segment number if it already exists.
     */
    FileSetSegmentName(name, buffile->name, segment + 1);
    FileSetDelete(buffile->fileset, name, true);
 
    /* Create the new segment. */
    FileSetSegmentName(name, buffile->name, segment);
    file = FileSetCreate(buffile->fileset, name);
 
    /* FileSetCreate would've errored out */
    Assert(file > 0);
 
    return file;
}

References Assert(), BufFile::fileset, FileSetCreate(), FileSetDelete(), FileSetSegmentName(), MAXPGPATH, BufFile::name, and name.

Referenced by BufFileCreateFileSet(), and extendBufFile().