greenplumn pxf_fdw 源码
greenplumn pxf_fdw 代码
文件路径：/gpcontrib/pxf_fdw/pxf_fdw.c
/*
* pxf_fdw.c
* Foreign-data wrapper for PXF (Platform Extension Framework)
*
* IDENTIFICATION
* contrib/pxf_fdw/pxf_fdw.c
*/
#include "postgres.h"
#include "pxf_fdw.h"
#include "pxf_bridge.h"
#include "pxf_filter.h"
#include "pxf_fragment.h"
#include "access/reloptions.h"
#include "access/table.h"
#include "cdb/cdbsreh.h"
#include "cdb/cdbvars.h"
#include "commands/copy.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "foreign/fdwapi.h"
#include "foreign/foreign.h"
#include "nodes/pg_list.h"
#include "optimizer/optimizer.h"
#include "optimizer/paths.h"
#include "optimizer/pathnode.h"
#include "optimizer/planmain.h"
#include "optimizer/restrictinfo.h"
#include "parser/parsetree.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
PG_MODULE_MAGIC;
#define DEFAULT_PXF_FDW_STARTUP_COST 50000
extern Datum pxf_fdw_handler(PG_FUNCTION_ARGS);
/*
* SQL functions
*/
PG_FUNCTION_INFO_V1(pxf_fdw_handler);
/*
* FDW functions declarations
*/
static void pxfGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid);
static void pxfGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid);
#if (PG_VERSION_NUM <= 90500)
static ForeignScan *pxfGetForeignPlan(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid, ForeignPath *best_path, List *tlist,
List *scan_clauses);
#else
static ForeignScan *pxfGetForeignPlan(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid, ForeignPath *best_path, List *tlist, List *scan_clauses, Plan *outer_plan);
#endif
static void pxfExplainForeignScan(ForeignScanState *node, ExplainState *es);
static void pxfBeginForeignScan(ForeignScanState *node, int eflags);
static TupleTableSlot *pxfIterateForeignScan(ForeignScanState *node);
static void pxfReScanForeignScan(ForeignScanState *node);
static void pxfEndForeignScan(ForeignScanState *node);
/* Foreign updates */
static void pxfBeginForeignModify(ModifyTableState *mtstate, ResultRelInfo *resultRelInfo, List *fdw_private, int subplan_index, int eflags);
static TupleTableSlot *pxfExecForeignInsert(EState *estate, ResultRelInfo *resultRelInfo, TupleTableSlot *slot, TupleTableSlot *planSlot);
static void pxfEndForeignModify(EState *estate, ResultRelInfo *resultRelInfo);
static int pxfIsForeignRelUpdatable(Relation rel);
/*
* Helper functions
*/
static void InitCopyState(PxfFdwScanState *pxfsstate);
static void InitCopyStateForModify(PxfFdwModifyState *pxfmstate);
static CopyState BeginCopyTo(Relation forrel, List *options);
/*
* Foreign-data wrapper handler functions:
* returns a struct with pointers to the
* pxf_fdw callback routines.
*/
Datum
pxf_fdw_handler(PG_FUNCTION_ARGS)
{
FdwRoutine *fdw_routine = makeNode(FdwRoutine);
/*
* foreign table scan support
*/
/* master - only */
fdw_routine->GetForeignRelSize = pxfGetForeignRelSize;
fdw_routine->GetForeignPaths = pxfGetForeignPaths;
fdw_routine->GetForeignPlan = pxfGetForeignPlan;
fdw_routine->ExplainForeignScan = pxfExplainForeignScan;
/* segment - only when mpp_execute = segments */
fdw_routine->BeginForeignScan = pxfBeginForeignScan;
fdw_routine->IterateForeignScan = pxfIterateForeignScan;
fdw_routine->ReScanForeignScan = pxfReScanForeignScan;
fdw_routine->EndForeignScan = pxfEndForeignScan;
/*
* foreign table insert support
*/
/*
* AddForeignUpdateTargets set to NULL, no extra target expressions are
* added
*/
fdw_routine->AddForeignUpdateTargets = NULL;
/*
* PlanForeignModify set to NULL, no additional plan-time actions are
* taken
*/
fdw_routine->PlanForeignModify = NULL;
fdw_routine->BeginForeignModify = pxfBeginForeignModify;
fdw_routine->ExecForeignInsert = pxfExecForeignInsert;
/*
* ExecForeignUpdate and ExecForeignDelete set to NULL since updates and
* deletes are not supported
*/
fdw_routine->ExecForeignUpdate = NULL;
fdw_routine->ExecForeignDelete = NULL;
fdw_routine->EndForeignModify = pxfEndForeignModify;
fdw_routine->IsForeignRelUpdatable = pxfIsForeignRelUpdatable;
PG_RETURN_POINTER(fdw_routine);
}
typedef struct PxfFdwRelationInfo
{
/* baserestrictinfo clauses, broken down into safe and unsafe subsets. */
List *remote_conds;
List *local_conds;
/* List of attributes (columns) that we need to get */
List *retrieved_attrs;
/* Bitmap of attr numbers we need to fetch from the remote server. */
Bitmapset *attrs_used;
} PxfFdwRelationInfo;
/*
* Indexes of FDW-private information stored in fdw_private lists.
*
* We store various information in ForeignScan.fdw_private to pass it from
* planner to executor. Currently we store:
*
* 1) WHERE clause text to be sent to the remote server
* 2) Integer list of attribute numbers retrieved by the SELECT
*
* These items are indexed with the enum FdwScanPrivateIndex, so an item
* can be fetched with list_nth(). For example, to get the WHERE clauses:
* sql = strVal(list_nth(fdw_private, FdwScanPrivateWhereClauses));
*/
enum FdwScanPrivateIndex
{
/* WHERE clauses to be sent to PXF (as a String node) */
FdwScanPrivateWhereClauses,
/* Integer list of attribute numbers retrieved by the SELECT */
FdwScanPrivateRetrievedAttrs,
/* List of fragments to be processed by the segments */
FdwScanPrivateFragmentList
};
/*
* GetForeignRelSize
* set relation size estimates for a foreign table
*/
static void
pxfGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
{
elog(DEBUG5, "pxf_fdw: pxfGetForeignRelSize starts on segment: %d", PXF_SEGMENT_ID);
Relation rel;
ListCell *lc;
PxfFdwRelationInfo *fpinfo = (PxfFdwRelationInfo *) palloc(sizeof(PxfFdwRelationInfo));
baserel->fdw_private = (void *) fpinfo;
fpinfo->attrs_used = NULL;
/*
* Core code already has some lock on each rel being planned, so we can
* use NoLock here.
*/
RangeTblEntry *rte = planner_rt_fetch(baserel->relid, root);
rel = table_open(rte->relid, NoLock);
/*
* Identify which baserestrictinfo clauses can be sent to the remote
* server and which can't.
*/
classifyConditions(root, baserel, baserel->baserestrictinfo,
&fpinfo->remote_conds, &fpinfo->local_conds);
/*
* Identify which attributes will need to be retrieved from the remote
* server
*/
#if (PG_VERSION_NUM <= 90500)
pull_varattnos((Node *) baserel->reltargetlist, baserel->relid, &fpinfo->attrs_used);
#else
pull_varattnos((Node *) baserel->reltarget->exprs, baserel->relid, &fpinfo->attrs_used);
#endif
foreach(lc, fpinfo->local_conds)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
pull_varattnos((Node *) rinfo->clause, baserel->relid, &fpinfo->attrs_used);
}
deparseTargetList(rel, fpinfo->attrs_used, &fpinfo->retrieved_attrs);
heap_close(rel, NoLock);
/* Use an artificial number of estimated rows */
baserel->rows = 1000;
elog(DEBUG5, "pxf_fdw: pxfGetForeignRelSize ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* GetForeignPaths
* create access path for a scan on the foreign table
*/
static void
pxfGetForeignPaths(PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid)
{
ForeignPath *path = NULL;
int total_cost = DEFAULT_PXF_FDW_STARTUP_COST;
PxfFdwRelationInfo *fpinfo = (PxfFdwRelationInfo *) baserel->fdw_private;
elog(DEBUG5, "pxf_fdw: pxfGetForeignPaths starts on segment: %d", PXF_SEGMENT_ID);
path = create_foreignscan_path(root, baserel,
#if PG_VERSION_NUM >= 90600
NULL, /* default pathtarget */
#endif
baserel->rows,
DEFAULT_PXF_FDW_STARTUP_COST,
total_cost,
NIL, /* no pathkeys */
NULL, /* no outer rel either */
#if PG_VERSION_NUM >= 90500
NULL, /* no extra plan */
#endif
fpinfo->retrieved_attrs);
/*
* Create a ForeignPath node and add it as only possible path.
*/
add_path(baserel, (Path *) path);
elog(DEBUG5, "pxf_fdw: pxfGetForeignPaths ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* GetForeignPlan
* create a ForeignScan plan node
*/
#if PG_VERSION_NUM >= 90500
static ForeignScan *
pxfGetForeignPlan(PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid,
ForeignPath *best_path,
List *tlist,
List *scan_clauses,
Plan *outer_plan)
#else
static ForeignScan *
pxfGetForeignPlan(PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid,
ForeignPath *best_path,
List *tlist, /* target list */
List *scan_clauses)
#endif
{
Index scan_relid = baserel->relid;
PxfFdwRelationInfo *fpinfo = (PxfFdwRelationInfo *) baserel->fdw_private;
List *fdw_private;
elog(DEBUG5, "pxf_fdw: pxfGetForeignPlan starts on segment: %d", PXF_SEGMENT_ID);
/*
* We have no native ability to evaluate restriction clauses, so we just
* put all the scan_clauses into the plan node's qual list for the
* executor to check. So all we have to do here is strip RestrictInfo
* nodes from the clauses and ignore pseudoconstants (which will be
* handled elsewhere).
*/
scan_clauses = extract_actual_clauses(scan_clauses, false);
/*
* Build the fdw_private list that will be available to the executor.
* Items in the list must match enum FdwScanPrivateIndex, above.
*/
/* here we serialize the WHERE clauses */
char *where_clauses_str = SerializePxfFilterQuals(fpinfo->remote_conds);
fdw_private = list_make2(makeString(where_clauses_str), fpinfo->retrieved_attrs);
elog(DEBUG5, "pxf_fdw: pxfGetForeignPlan ends on segment: %d", PXF_SEGMENT_ID);
return make_foreignscan(
tlist,
scan_clauses,
scan_relid,
NIL, /* no expressions to evaluate */
fdw_private
#if PG_VERSION_NUM >= 90500
,NIL
,NIL
,outer_plan
#endif
);
}
/*
* pxfExplainForeignScan
* Produce extra output for EXPLAIN of a ForeignScan on a foreign table
*/
static void
pxfExplainForeignScan(ForeignScanState *node, ExplainState *es)
{
elog(DEBUG5, "pxf_fdw: pxfExplainForeignScan starts on segment: %d", PXF_SEGMENT_ID);
/* TODO: make this a meaningful callback */
elog(DEBUG5, "pxf_fdw: pxfExplainForeignScan ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* BeginForeignScan
* called during executor startup. perform any initialization
* needed, but not start the actual scan.
*/
static void
pxfBeginForeignScan(ForeignScanState *node, int eflags)
{
elog(DEBUG5, "pxf_fdw: pxfBeginForeignScan starts on segment: %d", PXF_SEGMENT_ID);
/*
* Do nothing in EXPLAIN (no ANALYZE) case. node->fdw_state stays NULL.
*/
if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
return;
List* serializedFragmentList;
List* fragments;
ForeignTable *rel = GetForeignTable(RelationGetRelid(node->ss.ss_currentRelation));
ExprState *quals = node->ss.ps.qual;
Oid foreigntableid = RelationGetRelid(node->ss.ss_currentRelation);
PxfFdwScanState *pxfsstate = NULL;
Relation relation = node->ss.ss_currentRelation;
ForeignScan *foreignScan = (ForeignScan *) node->ss.ps.plan;
PxfOptions *options = PxfGetOptions(foreigntableid);
/* retrieve fdw-private information from pxfGetForeignPlan() */
char *filter_str = strVal(list_nth(foreignScan->fdw_private, FdwScanPrivateWhereClauses));
List *retrieved_attrs = (List *) list_nth(foreignScan->fdw_private, FdwScanPrivateRetrievedAttrs);
/*
* When running queries on all segments, master makes the fragmenter call
* and segments receive a List of FragmentData from master. When the query
* only runs on coordinator or any, the fragment list is retrieved by the
* executing process.
*/
if (rel->exec_location != FTEXECLOCATION_ALL_SEGMENTS || Gp_role == GP_ROLE_DISPATCH)
{
fragments = GetFragmentList(options,
relation,
filter_str,
retrieved_attrs);
if (Gp_role == GP_ROLE_DISPATCH)
{
/*
* serialize fragment list and pass it down to segments
* by appending it to foreignScan->fdw_private
*/
serializedFragmentList = SerializeFragmentList(fragments);
foreignScan->fdw_private = lappend(foreignScan->fdw_private, serializedFragmentList);
/* master does not process any fragments */
return;
}
}
else
{
serializedFragmentList = (List *) list_nth(foreignScan->fdw_private, FdwScanPrivateFragmentList);
fragments = DeserializeFragmentList(serializedFragmentList);
/*
* Call the work allocation algorithm when execution happens on all
* segments
*/
fragments = FilterFragmentsForSegment(fragments);
}
/* Assign PXF location for the allocated fragments */
AssignPxfLocationToFragments(options, fragments);
/*
* Save state in node->fdw_state. We must save enough information to call
* BeginCopyFrom() again.
*/
pxfsstate = (PxfFdwScanState *) palloc(sizeof(PxfFdwScanState));
initStringInfo(&pxfsstate->uri);
pxfsstate->filter_str = filter_str;
pxfsstate->fragments = fragments;
pxfsstate->options = options;
pxfsstate->quals = quals;
pxfsstate->relation = relation;
pxfsstate->retrieved_attrs = retrieved_attrs;
InitCopyState(pxfsstate);
node->fdw_state = (void *) pxfsstate;
elog(DEBUG5, "pxf_fdw: pxfBeginForeignScan ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* IterateForeignScan
* Retrieve next row from the result set, or clear tuple slot to indicate
* EOF.
* Fetch one row from the foreign source, returning it in a tuple table slot
* (the node's ScanTupleSlot should be used for this purpose).
* Return NULL if no more rows are available.
*/
static TupleTableSlot *
pxfIterateForeignScan(ForeignScanState *node)
{
elog(DEBUG5, "pxf_fdw: pxfIterateForeignScan Executing on segment: %d", PXF_SEGMENT_ID);
PxfFdwScanState *pxfsstate = (PxfFdwScanState *) node->fdw_state;
TupleTableSlot *slot = node->ss.ss_ScanTupleSlot;
ErrorContextCallback errcallback;
bool found;
/* Set up callback to identify error line number. */
errcallback.callback = CopyFromErrorCallback;
errcallback.arg = (void *) pxfsstate->cstate;
errcallback.previous = error_context_stack;
error_context_stack = &errcallback;
/*
* The protocol for loading a virtual tuple into a slot is first
* ExecClearTuple, then fill the values/isnull arrays, then
* ExecStoreVirtualTuple. If we don't find another row in the file, we
* just skip the last step, leaving the slot empty as required.
*
* We can pass ExprContext = NULL because we read all columns from the
* file, so no need to evaluate default expressions.
*/
ExecClearTuple(slot);
found = NextCopyFrom(pxfsstate->cstate,
NULL,
slot->tts_values,
slot->tts_isnull);
if (found)
{
if (pxfsstate->cstate->cdbsreh)
{
/*
* If NextCopyFrom failed, the processed row count will have
* already been updated, but we need to update it in a successful
* case.
*
* GPDB_91_MERGE_FIXME: this is almost certainly not the right
* place for this, but row counts are currently scattered all over
* the place. Consolidate.
*/
pxfsstate->cstate->cdbsreh->processed++;
}
ExecStoreVirtualTuple(slot);
}
/* Remove error callback. */
error_context_stack = errcallback.previous;
return slot;
}
/*
* ReScanForeignScan
* Restart the scan from the beginning
*/
static void
pxfReScanForeignScan(ForeignScanState *node)
{
elog(DEBUG5, "pxf_fdw: pxfReScanForeignScan starts on segment: %d", PXF_SEGMENT_ID);
PxfFdwScanState *pxfsstate = (PxfFdwScanState *) node->fdw_state;
EndCopyFrom(pxfsstate->cstate);
InitCopyState(pxfsstate);
elog(DEBUG5, "pxf_fdw: pxfReScanForeignScan ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* EndForeignScan
* End the scan and release resources.
*/
static void
pxfEndForeignScan(ForeignScanState *node)
{
elog(DEBUG5, "pxf_fdw: pxfEndForeignScan starts on segment: %d", PXF_SEGMENT_ID);
ForeignScan *foreignScan = (ForeignScan *) node->ss.ps.plan;
PxfFdwScanState *pxfsstate = (PxfFdwScanState *) node->fdw_state;
/* Release resources */
if (foreignScan->fdw_private)
{
elog(DEBUG5, "Freeing fdw_private");
pfree(foreignScan->fdw_private);
}
/* if pxfsstate is NULL, we are in EXPLAIN; nothing to do */
if (pxfsstate)
EndCopyFrom(pxfsstate->cstate);
elog(DEBUG5, "pxf_fdw: pxfEndForeignScan ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* pxfBeginForeignModify
* Begin an insert/update/delete operation on a foreign table
*/
static void
pxfBeginForeignModify(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
List *fdw_private,
int subplan_index,
int eflags)
{
elog(DEBUG5, "pxf_fdw: pxfBeginForeignModify starts on segment: %d", PXF_SEGMENT_ID);
PxfOptions *options = NULL;
PxfFdwModifyState *pxfmstate = NULL;
Relation relation = resultRelInfo->ri_RelationDesc;
TupleDesc tupDesc;
if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
return;
tupDesc = RelationGetDescr(relation);
options = PxfGetOptions(RelationGetRelid(relation));
pxfmstate = palloc(sizeof(PxfFdwModifyState));
initStringInfo(&pxfmstate->uri);
pxfmstate->relation = relation;
pxfmstate->options = options;
InitCopyStateForModify(pxfmstate);
resultRelInfo->ri_FdwState = pxfmstate;
elog(DEBUG5, "pxf_fdw: pxfBeginForeignModify ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* pxfExecForeignInsert
* Insert one row into a foreign table
*/
static TupleTableSlot *
pxfExecForeignInsert(EState *estate,
ResultRelInfo *resultRelInfo,
TupleTableSlot *slot,
TupleTableSlot *planSlot)
{
elog(DEBUG5, "pxf_fdw: pxfExecForeignInsert starts on segment: %d", PXF_SEGMENT_ID);
PxfFdwModifyState *pxfmstate = (PxfFdwModifyState *) resultRelInfo->ri_FdwState;
CopyState cstate = pxfmstate->cstate;
/* TEXT or CSV */
slot_getallattrs(slot);
CopyOneRowTo(cstate, slot);
CopySendEndOfRow(cstate);
StringInfo fe_msgbuf = cstate->fe_msgbuf;
int bytes_written = PxfBridgeWrite(pxfmstate, fe_msgbuf->data, fe_msgbuf->len);
if (bytes_written == -1)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write to foreign resource: %m")));
}
elog(DEBUG3, "pxf_fdw %d bytes written", bytes_written);
/* Reset our buffer to start clean next round */
cstate->fe_msgbuf->len = 0;
cstate->fe_msgbuf->data[0] = '\0';
elog(DEBUG5, "pxf_fdw: pxfExecForeignInsert ends on segment: %d", PXF_SEGMENT_ID);
return slot;
}
/*
* pxfEndForeignModify
* Finish an insert/update/delete operation on a foreign table
*/
static void
pxfEndForeignModify(EState *estate,
ResultRelInfo *resultRelInfo)
{
elog(DEBUG5, "pxf_fdw: pxfEndForeignModify starts on segment: %d", PXF_SEGMENT_ID);
PxfFdwModifyState *pxfmstate = (PxfFdwModifyState *) resultRelInfo->ri_FdwState;
/* If pxfmstate is NULL, we are in EXPLAIN; nothing to do */
if (pxfmstate == NULL)
return;
EndCopyFrom(pxfmstate->cstate);
PxfBridgeCleanup(pxfmstate);
elog(DEBUG5, "pxf_fdw: pxfEndForeignModify ends on segment: %d", PXF_SEGMENT_ID);
}
/*
* pxfIsForeignRelUpdatable
* Assume table is updatable regardless of settings.
* Determine whether a foreign table supports INSERT, UPDATE and/or
* DELETE.
*/
static int
pxfIsForeignRelUpdatable(Relation rel)
{
elog(DEBUG5, "pxf_fdw: pxfIsForeignRelUpdatable starts on segment: %d", PXF_SEGMENT_ID);
elog(DEBUG5, "pxf_fdw: pxfIsForeignRelUpdatable ends on segment: %d", PXF_SEGMENT_ID);
/* Only INSERTs are allowed at the moment */
return 1u << (unsigned int) CMD_INSERT | 0u << (unsigned int) CMD_UPDATE | 0u << (unsigned int) CMD_DELETE;
}
/*
* Initiates a copy state for pxfBeginForeignScan() and pxfReScanForeignScan()
*/
static void
InitCopyState(PxfFdwScanState *pxfsstate)
{
CopyState cstate;
PxfBridgeImportStart(pxfsstate);
/*
* Create CopyState from FDW options. We always acquire all columns, so
* as to match the expected ScanTupleSlot signature.
*/
cstate = BeginCopyFrom(NULL,
pxfsstate->relation,
NULL,
false, /* is_program */
&PxfBridgeRead, /* data_source_cb */
pxfsstate, /* data_source_cb_extra */
NIL, /* attnamelist */
pxfsstate->options->copy_options); /* copy options */
if (pxfsstate->options->reject_limit == -1)
{
/* Default error handling - "all-or-nothing" */
cstate->cdbsreh = NULL; /* no SREH */
cstate->errMode = ALL_OR_NOTHING;
}
else
{
/* no error log by default */
cstate->errMode = SREH_IGNORE;
/* select the SREH mode */
if (pxfsstate->options->log_errors)
cstate->errMode = SREH_LOG; /* errors into file */
cstate->cdbsreh = makeCdbSreh(pxfsstate->options->reject_limit,
pxfsstate->options->is_reject_limit_rows,
pxfsstate->options->resource,
(char *) cstate->cur_relname,
pxfsstate->options->log_errors ? LOG_ERRORS_ENABLE : LOG_ERRORS_DISABLE);
cstate->cdbsreh->relid = RelationGetRelid(pxfsstate->relation);
}
/* and 'fe_mgbuf' */
cstate->fe_msgbuf = makeStringInfo();
/*
* Create a temporary memory context that we can reset once per row to
* recover palloc'd memory. This avoids any problems with leaks inside
* datatype input or output routines, and should be faster than retail
* pfree's anyway.
*/
cstate->rowcontext = AllocSetContextCreate(CurrentMemoryContext,
"PxfFdwMemCxt",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
pxfsstate->cstate = cstate;
}
/*
* Initiates a copy state for pxfBeginForeignModify()
*/
static void
InitCopyStateForModify(PxfFdwModifyState *pxfmstate)
{
List *copy_options;
CopyState cstate;
copy_options = pxfmstate->options->copy_options;
PxfBridgeExportStart(pxfmstate);
/*
* Create CopyState from FDW options. We always acquire all columns, so
* as to match the expected ScanTupleSlot signature.
*/
cstate = BeginCopyTo(pxfmstate->relation, copy_options);
/* Initialize 'out_functions', like CopyTo() would. */
TupleDesc tupDesc = RelationGetDescr(cstate->rel);
Form_pg_attribute attr = tupDesc->attrs;
int num_phys_attrs = tupDesc->natts;
cstate->out_functions = (FmgrInfo *) palloc(num_phys_attrs * sizeof(FmgrInfo));
ListCell *cur;
foreach(cur, cstate->attnumlist)
{
int attnum = lfirst_int(cur);
Oid out_func_oid;
bool isvarlena;
getTypeOutputInfo(attr[attnum - 1].atttypid,
&out_func_oid,
&isvarlena);
fmgr_info(out_func_oid, &cstate->out_functions[attnum - 1]);
}
/* and 'fe_mgbuf' */
cstate->fe_msgbuf = makeStringInfo();
/*
* Create a temporary memory context that we can reset once per row to
* recover palloc'd memory. This avoids any problems with leaks inside
* datatype input or output routines, and should be faster than retail
* pfree's anyway.
*/
cstate->rowcontext = AllocSetContextCreate(CurrentMemoryContext,
"PxfFdwMemCxt",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
pxfmstate->cstate = cstate;
}
/*
* Set up CopyState for writing to an foreign table.
*/
static CopyState
BeginCopyTo(Relation forrel, List *options)
{
CopyState cstate;
Assert(forrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE);
#if (PG_VERSION_NUM <= 90500)
cstate = BeginCopy(false, forrel, NULL, NULL, NIL, options, NULL);
#else
cstate = BeginCopy(false, forrel, NULL, NULL, forrel->rd_id, NIL, options, NULL);
#endif
cstate->dispatch_mode = COPY_DIRECT;
/*
* We use COPY_CALLBACK to mean that the each line should be left in
* fe_msgbuf. There is no actual callback!
*/
cstate->copy_dest = COPY_CALLBACK;
/*
* Some more initialization, that in the normal COPY TO codepath, is done
* in CopyTo() itself.
*/
cstate->null_print_client = cstate->null_print; /* default */
if (cstate->need_transcoding)
cstate->null_print_client = pg_server_to_custom(cstate->null_print,
cstate->null_print_len,
cstate->file_encoding,
cstate->enc_conversion_proc);
return cstate;
}
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