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/*
* PgFincore
* This project let you see and mainpulate objects in the FS page cache
* Copyright (C) 2009-2011 Cédric Villemain
*/
/* { POSIX stuff */
#define _XOPEN_SOURCE 600 /* fadvise */
#include <stdlib.h> /* exit, calloc, free */
#include <sys/stat.h> /* stat, fstat */
#include <sys/types.h> /* size_t, mincore */
#include <unistd.h> /* sysconf, close */
#include <sys/mman.h> /* mmap, mincore */
#include <fcntl.h> /* fadvise */
/* } */
/* { PostgreSQL stuff */
#include "postgres.h" /* general Postgres declarations */
#include "access/heapam.h" /* relation_open */
#include "catalog/catalog.h" /* relpath */
#include "catalog/namespace.h" /* makeRangeVarFromNameList */
#include "utils/builtins.h" /* textToQualifiedNameList */
#include "utils/rel.h" /* Relation */
#include "utils/varbit.h" /* bitstring datatype */
#include "funcapi.h" /* SRF */
#include "catalog/pg_type.h" /* TEXTOID for tuple_desc */
#include "storage/fd.h"
#ifdef PG_VERSION_NUM
#define PG_MAJOR_VERSION (PG_VERSION_NUM / 100)
#else
#error "Unknown postgresql version"
#endif
#if PG_VERSION_NUM < 80300
#error "Unsupported postgresql version"
#endif
#if PG_VERSION_NUM > 90299
#include "access/htup_details.h" /* 9.3 heap_form_tuple */
#include "common/relpath.h" /* 9.3 relpathbackend */
#endif
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
/* } */
#define PGSYSCONF_COLS 3
#define PGFADVISE_COLS 4
#define PGFADVISE_LOADER_COLS 5
#define PGFINCORE_COLS 10
#define PGF_WILLNEED 10
#define PGF_DONTNEED 20
#define PGF_NORMAL 30
#define PGF_SEQUENTIAL 40
#define PGF_RANDOM 50
#define FINCORE_PRESENT 0x1
#define FINCORE_DIRTY 0x2
#ifndef HAVE_FINCORE
#define FINCORE_BITS 1
#else
#define FINCORE_BITS 2
#endif
/*
* pgfadvise_fctx structure is needed
* to keep track of relation path, segment number, ...
*/
typedef struct
{
int advice; /* the posix_fadvise advice */
TupleDesc tupd; /* the tuple descriptor */
Relation rel; /* the relation */
unsigned int segcount; /* the segment current number */
char *relationpath; /* the relation path */
} pgfadvise_fctx;
/*
* pgfadvise structure is needed
* to return values
*/
typedef struct
{
size_t pageSize; /* os page size */
size_t pagesFree; /* free page cache */
size_t filesize; /* the filesize */
} pgfadviseStruct;
/*
* pgfloader structure is needed
* to return values
*/
typedef struct
{
size_t pageSize; /* os page size */
size_t pagesFree; /* free page cache */
size_t pagesLoaded; /* pages loaded */
size_t pagesUnloaded; /* pages unloaded */
} pgfloaderStruct;
/*
* pgfincore_fctx structure is needed
* to keep track of relation path, segment number, ...
*/
typedef struct
{
bool getvector; /* output varbit data ? */
TupleDesc tupd; /* the tuple descriptor */
Relation rel; /* the relation */
unsigned int segcount; /* the segment current number */
char *relationpath; /* the relation path */
} pgfincore_fctx;
/*
* pgfadvise_loader_struct structure is needed
* to keep track of relation path, segment number, ...
*/
typedef struct
{
size_t pageSize; /* os page size */
size_t pagesFree; /* free page cache */
size_t rel_os_pages;
size_t pages_mem;
size_t group_mem;
size_t pages_dirty;
size_t group_dirty;
VarBit *databit;
} pgfincoreStruct;
Datum pgsysconf(PG_FUNCTION_ARGS);
Datum pgfadvise(PG_FUNCTION_ARGS);
static int pgfadvise_file(char *filename, int advice, pgfadviseStruct *pgfdv);
Datum pgfadvise_loader(PG_FUNCTION_ARGS);
static int pgfadvise_loader_file(char *filename,
bool willneed, bool dontneed,
VarBit *databit,
pgfloaderStruct *pgfloader);
Datum pgfincore(PG_FUNCTION_ARGS);
static int pgfincore_file(char *filename, pgfincoreStruct *pgfncr);
Datum pgfincore_drawer(PG_FUNCTION_ARGS);
/*
* We need to add some handler to keep the code clean
* and support 8.3, 8.4 and 9.0
*/
#if PG_MAJOR_VERSION == 803
#if defined(HAVE_DECL_POSIX_FADVISE)
#define USE_POSIX_FADVISE
#endif
char *text_to_cstring(const text *t);
text *cstring_to_text(const char *s);
text *cstring_to_text_with_len(const char *s, int len);
char *
text_to_cstring(const text *t)
{
/* must cast away the const, unfortunately */
text *tunpacked = pg_detoast_datum_packed((struct varlena *) t);
int len = VARSIZE_ANY_EXHDR(tunpacked);
char *result;
result = (char *) palloc(len + 1);
memcpy(result, VARDATA_ANY(tunpacked), len);
result[len] = '\0';
if (tunpacked != t)
pfree(tunpacked);
return result;
}
text *
cstring_to_text_with_len(const char *s, int len)
{
text *result = (text *) palloc(len + VARHDRSZ);
SET_VARSIZE(result, len + VARHDRSZ);
memcpy(VARDATA(result), s, len);
return result;
}
text *
cstring_to_text(const char *s)
{
return cstring_to_text_with_len(s, strlen(s));
}
#define CStringGetTextDatum(s) PointerGetDatum(cstring_to_text(s))
#define relpathpg(rel, forkName) \
relpath((rel)->rd_node)
#elif PG_MAJOR_VERSION == 804 || PG_MAJOR_VERSION == 900
#define relpathpg(rel, forkName) \
relpath((rel)->rd_node, forkname_to_number(text_to_cstring(forkName)))
#else
#define relpathpg(rel, forkName) \
relpathbackend((rel)->rd_node, (rel)->rd_backend, (forkname_to_number(text_to_cstring(forkName))))
#endif
/*
* pgsysconf
* just output the actual system value for
* _SC_PAGESIZE --> Page Size
* _SC_AVPHYS_PAGES --> Free page in memory
* _SC_PHYS_PAGES --> Total memory
*
*/
PG_FUNCTION_INFO_V1(pgsysconf);
Datum
pgsysconf(PG_FUNCTION_ARGS)
{
HeapTuple tuple;
TupleDesc tupdesc;
Datum values[PGSYSCONF_COLS];
bool nulls[PGSYSCONF_COLS];
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "pgsysconf: return type must be a row type");
/* Page size */
values[0] = Int64GetDatum(sysconf(_SC_PAGESIZE));
/* free page in memory */
values[1] = Int64GetDatum(sysconf(_SC_AVPHYS_PAGES));
/* total memory */
values[2] = Int64GetDatum(sysconf(_SC_PHYS_PAGES));
/* Build and return the result tuple. */
tuple = heap_form_tuple(tupdesc, values, nulls);
PG_RETURN_DATUM( HeapTupleGetDatum(tuple) );
}
#if defined(USE_POSIX_FADVISE)
/*
* pgfadvise_file
*/
static int
pgfadvise_file(char *filename, int advice, pgfadviseStruct *pgfdv)
{
/*
* We use the AllocateFile(2) provided by PostgreSQL. We're going to
* close it ourselves even if PostgreSQL close it anyway at transaction
* end.
*/
FILE *fp;
int fd;
struct stat st;
int adviceFlag;
/*
* OS Page size and Free pages
*/
pgfdv->pageSize = sysconf(_SC_PAGESIZE);
/*
* Fopen and fstat file
* fd will be provided to posix_fadvise
* if there is no file, just return 1, it is expected to leave the SRF
*/
fp = AllocateFile(filename, "rb");
if (fp == NULL)
return 1;
fd = fileno(fp);
if (fstat(fd, &st) == -1)
{
FreeFile(fp);
elog(ERROR, "pgfadvise: Can not stat object file : %s", filename);
return 2;
}
/*
* the file size is used in the SRF to output the number of pages used by
* the segment
*/
pgfdv->filesize = st.st_size;
elog(DEBUG1, "pgfadvise: working on %s of %lld bytes",
filename, (long long int) pgfdv->filesize);
/* FADVISE_WILLNEED */
if (advice == PGF_WILLNEED)
{
adviceFlag = POSIX_FADV_WILLNEED;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_WILLNEED");
}
/* FADVISE_DONTNEED */
else if (advice == PGF_DONTNEED)
{
adviceFlag = POSIX_FADV_DONTNEED;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_DONTNEED");
}
/* POSIX_FADV_NORMAL */
else if (advice == PGF_NORMAL)
{
adviceFlag = POSIX_FADV_NORMAL;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_NORMAL");
}
/* POSIX_FADV_SEQUENTIAL */
else if (advice == PGF_SEQUENTIAL)
{
adviceFlag = POSIX_FADV_SEQUENTIAL;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_SEQUENTIAL");
}
/* POSIX_FADV_RANDOM */
else if (advice == PGF_RANDOM)
{
adviceFlag = POSIX_FADV_RANDOM;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_RANDOM");
}
else
{
elog(ERROR, "pgfadvise: invalid advice: %d", advice);
return 2;
}
/*
* Call posix_fadvise with the relevant advice on the file descriptor
*/
posix_fadvise(fd, 0, 0, adviceFlag);
/* close the file */
FreeFile(fp);
/*
* OS things : Pages free
*/
pgfdv->pagesFree = sysconf(_SC_AVPHYS_PAGES);
return 0;
}
#else
static int
pgfadvise_file(char *filename, int advice, pgfadviseStruct *pgfdv)
{
elog(ERROR, "POSIX_FADVISE UNSUPPORTED on your platform");
return 9;
}
#endif
/*
* pgfadvise is a function that handle the process to have a sharelock
* on the relation and to walk the segments.
* for each segment it call the posix_fadvise with the required flag
* parameter
*/
PG_FUNCTION_INFO_V1(pgfadvise);
Datum
pgfadvise(PG_FUNCTION_ARGS)
{
/* SRF Stuff */
FuncCallContext *funcctx;
pgfadvise_fctx *fctx;
/* our structure use to return values */
pgfadviseStruct *pgfdv;
/* our return value, 0 for success */
int result;
/* The file we are working on */
char filename[MAXPGPATH];
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
MemoryContext oldcontext;
Oid relOid = PG_GETARG_OID(0);
text *forkName = PG_GETARG_TEXT_P(1);
int advice = PG_GETARG_INT32(2);
/*
* Postgresql stuff to return a tuple
*/
TupleDesc tupdesc;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* allocate memory for user context */
fctx = (pgfadvise_fctx *) palloc(sizeof(pgfadvise_fctx));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "pgfadvise: return type must be a row type");
/* provide the tuple descriptor to the fonction structure */
fctx->tupd = tupdesc;
/* open the current relation, accessShareLock */
// TODO use try_relation_open instead ?
fctx->rel = relation_open(relOid, AccessShareLock);
/* we get the common part of the filename of each segment of a relation */
fctx->relationpath = relpathpg(fctx->rel, forkName);
/* Here we keep track of current action in all calls */
fctx->advice = advice;
/* segcount is used to get the next segment of the current relation */
fctx->segcount = 0;
/* And finally we keep track of our initialization */
elog(DEBUG1, "pgfadvise: init done for %s, in fork %s",
fctx->relationpath, text_to_cstring(forkName));
funcctx->user_fctx = fctx;
MemoryContextSwitchTo(oldcontext);
}
/* After the first call, we recover our context */
funcctx = SRF_PERCALL_SETUP();
fctx = funcctx->user_fctx;
/*
* If we are still looking the first segment
* relationpath should not be suffixed
*/
if (fctx->segcount == 0)
snprintf(filename,
MAXPGPATH,
"%s",
fctx->relationpath);
else
snprintf(filename,
MAXPGPATH,
"%s.%u",
fctx->relationpath,
fctx->segcount);
elog(DEBUG1, "pgfadvise: about to work with %s, current advice : %d",
filename, fctx->advice);
/*
* Call posix_fadvise with the advice, returning the structure
*/
pgfdv = (pgfadviseStruct *) palloc(sizeof(pgfadviseStruct));
result = pgfadvise_file(filename, fctx->advice, pgfdv);
/*
* When we have work with all segments of the current relation
* We exit from the SRF
* Else we build and return the tuple for this segment
*/
if (result)
{
elog(DEBUG1, "pgfadvise: closing %s", fctx->relationpath);
relation_close(fctx->rel, AccessShareLock);
pfree(fctx);
SRF_RETURN_DONE(funcctx);
}
else {
/*
* Postgresql stuff to return a tuple
*/
HeapTuple tuple;
Datum values[PGFADVISE_COLS];
bool nulls[PGFADVISE_COLS];
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* prepare the number of the next segment */
fctx->segcount++;
/* Filename */
values[0] = CStringGetTextDatum( filename );
/* os page size */
values[1] = Int64GetDatum( (int64) pgfdv->pageSize );
/* number of pages used by segment */
values[2] = Int64GetDatum( (int64) ((pgfdv->filesize+pgfdv->pageSize-1)/pgfdv->pageSize) );
/* free page cache */
values[3] = Int64GetDatum( (int64) pgfdv->pagesFree );
/* Build the result tuple. */
tuple = heap_form_tuple(fctx->tupd, values, nulls);
/* Ok, return results, and go for next call */
SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
}
}
#if defined(USE_POSIX_FADVISE)
/*
* pgfadvise_file
*/
static int
pgfadvise_loader_file(char *filename,
bool willneed, bool dontneed, VarBit *databit,
pgfloaderStruct *pgfloader)
{
bits8 *sp;
int bitlen;
bits8 x;
int i, k;
/*
* We use the AllocateFile(2) provided by PostgreSQL. We're going to
* close it ourselves even if PostgreSQL close it anyway at transaction
* end.
*/
FILE *fp;
int fd;
struct stat st;
/*
* OS things : Page size
*/
pgfloader->pageSize = sysconf(_SC_PAGESIZE);
/*
* we count the action we perform
* both are theorical : we don't know if the page was or not in memory
* when we call posix_fadvise
*/
pgfloader->pagesLoaded = 0;
pgfloader->pagesUnloaded = 0;
/*
* Fopen and fstat file
* fd will be provided to posix_fadvise
* if there is no file, just return 1, it is expected to leave the SRF
*/
fp = AllocateFile(filename, "rb");
if (fp == NULL)
return 1;
fd = fileno(fp);
if (fstat(fd, &st) == -1)
{
FreeFile(fp);
elog(ERROR, "pgfadvise_loader: Can not stat object file: %s", filename);
return 2;
}
elog(DEBUG1, "pgfadvise_loader: working on %s", filename);
bitlen = VARBITLEN(databit);
sp = VARBITS(databit);
for (i = 0; i < bitlen - BITS_PER_BYTE; i += BITS_PER_BYTE, sp++)
{
x = *sp;
/* Is this bit set ? */
for (k = 0; k < BITS_PER_BYTE; k++)
{
if (IS_HIGHBIT_SET(x))
{
if (willneed)
{
(void) posix_fadvise(fd,
((i+k) * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_WILLNEED);
pgfloader->pagesLoaded++;
}
}
else if (dontneed)
{
(void) posix_fadvise(fd,
((i+k) * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_DONTNEED);
pgfloader->pagesUnloaded++;
}
x <<= 1;
}
}
/*
* XXX this copy/paste of code to finnish to walk the bits is not pretty
*/
if (i < bitlen)
{
/* print the last partial byte */
x = *sp;
for (k = i; k < bitlen; k++)
{
if (IS_HIGHBIT_SET(x))
{
if (willneed)
{
(void) posix_fadvise(fd,
(k * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_WILLNEED);
pgfloader->pagesLoaded++;
}
}
else if (dontneed)
{
(void) posix_fadvise(fd,
(k * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_DONTNEED);
pgfloader->pagesUnloaded++;
}
x <<= 1;
}
}
FreeFile(fp);
/*
* OS things : Pages free
*/
pgfloader->pagesFree = sysconf(_SC_AVPHYS_PAGES);
return 0;
}
#else
static int
pgfadvise_loader_file(char *filename,
bool willneed, bool dontneed, VarBit *databit,
pgfloaderStruct *pgfloader)
{
elog(ERROR, "POSIX_FADVISE UNSUPPORTED on your platform");
return 9;
}
#endif
/*
*
* pgfadv_loader to handle work with varbit map of buffer cache.
* it is actually used for loading/unloading block to/from buffer cache
*
*/
PG_FUNCTION_INFO_V1(pgfadvise_loader);
Datum
pgfadvise_loader(PG_FUNCTION_ARGS)
{
Oid relOid = PG_GETARG_OID(0);
text *forkName = PG_GETARG_TEXT_P(1);
int segmentNumber = PG_GETARG_INT32(2);
bool willneed = PG_GETARG_BOOL(3);
bool dontneed = PG_GETARG_BOOL(4);
VarBit *databit;
/* our structure use to return values */
pgfloaderStruct *pgfloader;
Relation rel;
char *relationpath;
char filename[MAXPGPATH];
/* our return value, 0 for success */
int result;
/*
* Postgresql stuff to return a tuple
*/
HeapTuple tuple;
TupleDesc tupdesc;
Datum values[PGFADVISE_LOADER_COLS];
bool nulls[PGFADVISE_LOADER_COLS];
if (PG_ARGISNULL(5))
elog(ERROR, "pgfadvise_loader: databit argument shouldn't be NULL");
databit = PG_GETARG_VARBIT_P(5);
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* open the current relation in accessShareLock */
rel = relation_open(relOid, AccessShareLock);
/* we get the common part of the filename of each segment of a relation */
relationpath = relpathpg(rel, forkName);
/*
* If we are looking the first segment,
* relationpath should not be suffixed
*/
if (segmentNumber == 0)
snprintf(filename,
MAXPGPATH,
"%s",
relationpath);
else
snprintf(filename,
MAXPGPATH,
"%s.%u",
relationpath,
(int) segmentNumber);
/*
* We don't need the relation anymore
* the only purpose was to get a consistent filename
* (if file disappear, an error is logged)
*/
relation_close(rel, AccessShareLock);
/*
* Call pgfadvise_loader with the varbit
*/
pgfloader = (pgfloaderStruct *) palloc(sizeof(pgfloaderStruct));
result = pgfadvise_loader_file(filename,
willneed, dontneed, databit,
pgfloader);
if (result != 0)
elog(ERROR, "Can't read file %s, fork(%s)",
filename, text_to_cstring(forkName));
/* Filename */
values[0] = CStringGetTextDatum( filename );
/* os page size */
values[1] = Int64GetDatum( pgfloader->pageSize );
/* free page cache */
values[2] = Int64GetDatum( pgfloader->pagesFree );
/* pages loaded */
values[3] = Int64GetDatum( pgfloader->pagesLoaded );
/* pages unloaded */
values[4] = Int64GetDatum( pgfloader->pagesUnloaded );
/* Build and return the result tuple. */
tuple = heap_form_tuple(tupdesc, values, nulls);
PG_RETURN_DATUM( HeapTupleGetDatum(tuple) );
}
/*
* pgfincore_file handle the mmaping, mincore process (and access file, etc.)
*/
static int
pgfincore_file(char *filename, pgfincoreStruct *pgfncr)
{
int flag=1;
int flag_dirty=1;
int len, bitlen;
bits8 *r;
bits8 x = 0;
register int64 pageIndex;
/*
* We use the AllocateFile(2) provided by PostgreSQL. We're going to
* close it ourselves even if PostgreSQL close it anyway at transaction
* end.
*/
FILE *fp;
int fd;
struct stat st;
#ifndef HAVE_FINCORE
void *pa = (char *) 0;
#endif
unsigned char *vec = (unsigned char *) 0;
/*
* OS Page size
*/
pgfncr->pageSize = sysconf(_SC_PAGESIZE);
/*
* Initialize counters
*/
pgfncr->pages_mem = 0;
pgfncr->group_mem = 0;
pgfncr->pages_dirty = 0;
pgfncr->group_dirty = 0;
pgfncr->rel_os_pages = 0;
/*
* Fopen and fstat file
* fd will be provided to posix_fadvise
* if there is no file, just return 1, it is expected to leave the SRF
*/
fp = AllocateFile(filename, "rb");
if (fp == NULL)
return 1;
fd = fileno(fp);
if (fstat(fd, &st) == -1)
{
FreeFile(fp);
elog(ERROR, "Can not stat object file : %s",
filename);
return 2;
}
/*
* if file ok
* then process
*/
if (st.st_size != 0)
{
/* number of pages in the current file */
pgfncr->rel_os_pages = (st.st_size+pgfncr->pageSize-1)/pgfncr->pageSize;
#ifndef HAVE_FINCORE
pa = mmap(NULL, st.st_size, PROT_NONE, MAP_SHARED, fd, 0);
if (pa == MAP_FAILED)
{
int save_errno = errno;
FreeFile(fp);
elog(ERROR, "Can not mmap object file : %s, errno = %i,%s\nThis error can happen if there is not enought space in memory to do the projection. Please mail cedric@villemain.org with '[pgfincore] ENOMEM' as subject.",
filename, save_errno, strerror(save_errno));
return 3;
}
#endif
/* Prepare our vector containing all blocks information */
vec = calloc(1, (st.st_size+pgfncr->pageSize-1)/pgfncr->pageSize);
if ((void *)0 == vec)
{
#ifndef HAVE_FINCORE
munmap(pa, st.st_size);
#endif
FreeFile(fp);
elog(ERROR, "Can not calloc object file : %s",
filename);
return 4;
}
#ifndef HAVE_FINCORE
/* Affect vec with mincore */
if (mincore(pa, st.st_size, vec) != 0)
{
int save_errno = errno;
munmap(pa, st.st_size);
elog(ERROR, "mincore(%p, %lld, %p): %s\n",
pa, (long long int)st.st_size, vec, strerror(save_errno));
#else
/* Affect vec with fincore */
if (fincore(fd, 0, st.st_size, vec) != 0)
{
int save_errno = errno;
elog(ERROR, "fincore(%u, 0, %lld, %p): %s\n",
fd, (long long int)st.st_size, vec, strerror(save_errno));
#endif
free(vec);
FreeFile(fp);
return 5;
}
/*
* prepare the bit string
*/
bitlen = FINCORE_BITS * ((st.st_size+pgfncr->pageSize-1)/pgfncr->pageSize);
len = VARBITTOTALLEN(bitlen);
/*
* set to 0 so that *r is always initialised and string is zero-padded
* XXX: do we need to free that ?
*/
pgfncr->databit = (VarBit *) palloc0(len);
SET_VARSIZE(pgfncr->databit, len);
VARBITLEN(pgfncr->databit) = bitlen;
r = VARBITS(pgfncr->databit);
x = HIGHBIT;
/* handle the results */
for (pageIndex = 0; pageIndex <= pgfncr->rel_os_pages; pageIndex++)
{
// block in memory
if (vec[pageIndex] & FINCORE_PRESENT)
{
pgfncr->pages_mem++;
*r |= x;
if (FINCORE_BITS > 1)
{
if (vec[pageIndex] & FINCORE_DIRTY)
{
pgfncr->pages_dirty++;
*r |= (x >> 1);
/* we flag to detect contigous blocks in the same state */
if (flag_dirty)
pgfncr->group_dirty++;
flag_dirty = 0;
}
else
flag_dirty = 1;
}
elog (DEBUG5, "in memory blocks : %lld / %lld",
(long long int) pageIndex, (long long int) pgfncr->rel_os_pages);
/* we flag to detect contigous blocks in the same state */
if (flag)
pgfncr->group_mem++;
flag = 0;
}
else
flag=1;
x >>= FINCORE_BITS;
if (x == 0)
{
x = HIGHBIT;
r++;
}
}
}
elog(DEBUG1, "pgfincore %s: %lld of %lld block in linux cache, %lld groups",
filename, (long long int) pgfncr->pages_mem, (long long int) pgfncr->rel_os_pages, (long long int) pgfncr->group_mem);
/*
* free and close
*/
free(vec);
#ifndef HAVE_FINCORE
munmap(pa, st.st_size);
#endif
FreeFile(fp);
/*
* OS things : Pages free
*/
pgfncr->pagesFree = sysconf(_SC_AVPHYS_PAGES);
return 0;
}
/*
* pgfincore is a function that handle the process to have a sharelock
* on the relation and to walk the segments.
* for each segment it call the appropriate function depending on 'action'
* parameter
*/
PG_FUNCTION_INFO_V1(pgfincore);
Datum
pgfincore(PG_FUNCTION_ARGS)
{
/* SRF Stuff */
FuncCallContext *funcctx;
pgfincore_fctx *fctx;
/* our structure use to return values */
pgfincoreStruct *pgfncr;
/* our return value, 0 for success */
int result;
/* The file we are working on */
char filename[MAXPGPATH];
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
MemoryContext oldcontext;
Oid relOid = PG_GETARG_OID(0);
text *forkName = PG_GETARG_TEXT_P(1);
bool getvector = PG_GETARG_BOOL(2);
/*
* Postgresql stuff to return a tuple
*/
TupleDesc tupdesc;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* allocate memory for user context */
fctx = (pgfincore_fctx *) palloc(sizeof(pgfincore_fctx));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "pgfadvise: return type must be a row type");
/* provide the tuple descriptor to the fonction structure */
fctx->tupd = tupdesc;
/* are we going to grab and output the varbit data (can be large) */
fctx->getvector = getvector;
/* open the current relation, accessShareLock */
// TODO use try_relation_open instead ?
fctx->rel = relation_open(relOid, AccessShareLock);
/* we get the common part of the filename of each segment of a relation */
fctx->relationpath = relpathpg(fctx->rel, forkName);
/* segcount is used to get the next segment of the current relation */
fctx->segcount = 0;
/* And finally we keep track of our initialization */
elog(DEBUG1, "pgfincore: init done for %s, in fork %s",
fctx->relationpath, text_to_cstring(forkName));
funcctx->user_fctx = fctx;
MemoryContextSwitchTo(oldcontext);
}
/* After the first call, we recover our context */
funcctx = SRF_PERCALL_SETUP();
fctx = funcctx->user_fctx;
/*
* If we are still looking the first segment
* relationpath should not be suffixed
*/
if (fctx->segcount == 0)
snprintf(filename,
MAXPGPATH,
"%s",
fctx->relationpath);
else
snprintf(filename,
MAXPGPATH,
"%s.%u",
fctx->relationpath,
fctx->segcount);
elog(DEBUG1, "pgfincore: about to work with %s", filename);
/*
* Call pgfincore with the advice, returning the structure
*/
pgfncr = (pgfincoreStruct *) palloc(sizeof(pgfincoreStruct));
result = pgfincore_file(filename, pgfncr);
/*
* When we have work with all segment of the current relation, test success
* We exit from the SRF
*/
if (result)
{
elog(DEBUG1, "pgfincore: closing %s", fctx->relationpath);
relation_close(fctx->rel, AccessShareLock);
pfree(fctx);
SRF_RETURN_DONE(funcctx);
}
else
{
/*
* Postgresql stuff to return a tuple
*/
HeapTuple tuple;
Datum values[PGFINCORE_COLS];
bool nulls[PGFINCORE_COLS];
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* Filename */
values[0] = CStringGetTextDatum(filename);
/* Segment Number */
values[1] = Int32GetDatum(fctx->segcount);
/* os page size */
values[2] = Int64GetDatum(pgfncr->pageSize);
/* number of pages used by segment */
values[3] = Int64GetDatum(pgfncr->rel_os_pages);
/* number of pages in OS cache */
values[4] = Int64GetDatum(pgfncr->pages_mem);
/* number of group of contigous page in os cache */
values[5] = Int64GetDatum(pgfncr->group_mem);
/* free page cache */
values[6] = Int64GetDatum(pgfncr->pagesFree);
/* the map of the file with bit set for in os cache page */
if (fctx->getvector && pgfncr->rel_os_pages)
{
values[7] = VarBitPGetDatum(pgfncr->databit);
}
else
{
nulls[7] = true;
values[7] = (Datum) NULL;
}
/* number of pages dirty in OS cache */
values[8] = Int64GetDatum(pgfncr->pages_dirty);
/* number of group of contigous dirty pages in os cache */
values[9] = Int64GetDatum(pgfncr->group_dirty);
/* Build the result tuple. */
tuple = heap_form_tuple(fctx->tupd, values, nulls);
/* prepare the number of the next segment */
fctx->segcount++;
/* Ok, return results, and go for next call */
SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
}
}
/*
* pgfincore_drawer A very naive renderer. (for testing)
*/
PG_FUNCTION_INFO_V1(pgfincore_drawer);
Datum
pgfincore_drawer(PG_FUNCTION_ARGS)
{
char *result,
*r;
int len,i,k;
VarBit *databit;
bits8 *sp;
bits8 x;
if (PG_ARGISNULL(0))
elog(ERROR, "pgfincore_drawer: databit argument shouldn't be NULL");
databit = PG_GETARG_VARBIT_P(0);
len = VARBITLEN(databit);
result = (char *) palloc((len/FINCORE_BITS) + 1);
sp = VARBITS(databit);
r = result;
for (i = 0; i <= len - BITS_PER_BYTE; i += BITS_PER_BYTE, sp++)
{
x = *sp;
/* Is this bit set ? */
for (k = 0; k < (BITS_PER_BYTE/FINCORE_BITS); k++)
{
char out = ' ';
if (IS_HIGHBIT_SET(x))
out = '.' ;
x <<= 1;
if (FINCORE_BITS > 1)
{
if (IS_HIGHBIT_SET(x))
out = '*';
x <<= 1;
}
*r++ = out;
}
}
if (i < len)
{
/* print the last partial byte */
x = *sp;
for (k = i; k < (len/FINCORE_BITS); k++)
{
char out = ' ';
if (IS_HIGHBIT_SET(x))
out = '.' ;
x <<= 1;
if (FINCORE_BITS > 1)
{
if (IS_HIGHBIT_SET(x))
out = '*';
x <<= 1;
}
*r++ = out;
}
}
*r = '\0';
PG_RETURN_CSTRING(result);
}
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