/
jdbc_fdw.c
1121 lines (957 loc) · 26.5 KB
/
jdbc_fdw.c
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/*-------------------------------------------------------------------------
*
* foreign-data wrapper for JDBC
*
* Copyright (c) 2012, PostgreSQL Global Development Group
*
* This software is released under the PostgreSQL Licence
*
* Author: Atri Sharma <atri.jiit@gmail.com>
*
* IDENTIFICATION
* jdbc_fdw/jdbc_fdw.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
#include <libpq/pqsignal.h>
#include "funcapi.h"
#include "access/reloptions.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_foreign_table.h"
#include "catalog/pg_user_mapping.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "foreign/fdwapi.h"
#include "foreign/foreign.h"
#include "miscadmin.h"
#include "mb/pg_wchar.h"
#include "optimizer/cost.h"
#include "storage/fd.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/rel.h"
#include "storage/ipc.h"
#if (PG_VERSION_NUM >= 90200)
#include "optimizer/pathnode.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/planmain.h"
#endif
#include "jni.h"
#define Str(arg) #arg
#define StrValue(arg) Str(arg)
#define STR_PKGLIBDIR StrValue(PKG_LIB_DIR)
PG_MODULE_MAGIC;
static JNIEnv *env;
static JavaVM *jvm;
jobject java_call;
static bool InterruptFlag; /* Used for checking for SIGINT interrupt */
/*
* Describes the valid options for objects that use this wrapper.
*/
struct jdbcFdwOption
{
const char *optname;
Oid optcontext; /* Oid of catalog in which option may appear */
};
/*
* Valid options for jdbc_fdw.
*
*/
static struct jdbcFdwOption valid_options[] =
{
/* Connection options */
{ "drivername", ForeignServerRelationId },
{ "url", ForeignServerRelationId },
{ "querytimeout", ForeignServerRelationId },
{ "jarfile", ForeignServerRelationId },
{ "maxheapsize", ForeignServerRelationId },
{ "username", UserMappingRelationId },
{ "password", UserMappingRelationId },
{ "query", ForeignTableRelationId },
{ "table", ForeignTableRelationId },
/* Sentinel */
{ NULL, InvalidOid }
};
/*
* FDW-specific information for ForeignScanState.fdw_state.
*/
typedef struct jdbcFdwExecutionState
{
char *query;
int NumberOfRows;
jobject java_call;
int NumberOfColumns;
} jdbcFdwExecutionState;
/*
* SQL functions
*/
extern Datum jdbc_fdw_handler(PG_FUNCTION_ARGS);
extern Datum jdbc_fdw_validator(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(jdbc_fdw_handler);
PG_FUNCTION_INFO_V1(jdbc_fdw_validator);
/*
* FDW callback routines
*/
#if (PG_VERSION_NUM < 90200)
static FdwPlan *jdbcPlanForeignScan(Oid foreigntableid,PlannerInfo *root, RelOptInfo *baserel);
#endif
#if (PG_VERSION_NUM >= 90200)
static void jdbcGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid);
static void jdbcGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid);
static ForeignScan *jdbcGetForeignPlan(
PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid,
ForeignPath *best_path,
List *tlist,
List *scan_clauses
#if PG_VERSION_NUM >= 90500
,
/*
* Require PostgreSQL >= 9.5
*/
Plan *outer_plan
#endif
);
#endif
static void jdbcExplainForeignScan(ForeignScanState *node, ExplainState *es);
static void jdbcBeginForeignScan(ForeignScanState *node, int eflags);
static TupleTableSlot *jdbcIterateForeignScan(ForeignScanState *node);
static void jdbcReScanForeignScan(ForeignScanState *node);
static void jdbcEndForeignScan(ForeignScanState *node);
/*
* Helper functions
*/
static bool jdbcIsValidOption(const char *option, Oid context);
static void jdbcGetOptions(
Oid foreigntableid,
char **drivername,
char **url,
int *querytimeout,
char **jarfile,
int* maxheapsize,
char **username,
char **password,
char **query,
char **table
);
/*
* Uses a String object's content to create an instance of C String
*/
static char* ConvertStringToCString(jobject);
/*
* JVM Initialization function
*/
static void JVMInitialization(Oid);
/*
* JVM destroy function
*/
static void DestroyJVM();
/*
* SIGINT interrupt handler
*/
static void SIGINTInterruptHandler(int);
/*
* SIGINT interrupt check and process function
*/
static void SIGINTInterruptCheckProcess();
/*
* SIGINTInterruptCheckProcess
* Checks and processes if SIGINT interrupt occurs
*/
static void
SIGINTInterruptCheckProcess()
{
if (InterruptFlag == true)
{
jclass JDBCUtilsClass;
jmethodID id_cancel;
jstring cancel_result = NULL;
char *cancel_result_cstring = NULL;
JDBCUtilsClass = (*env)->FindClass(env, "JDBCUtils");
if (JDBCUtilsClass == NULL)
{
elog(ERROR, "JDBCUtilsClass is NULL");
}
id_cancel = (*env)->GetMethodID(env, JDBCUtilsClass, "Cancel", "()Ljava/lang/String;");
if (id_cancel == NULL)
{
elog(ERROR, "id_cancel is NULL");
}
cancel_result = (*env)->CallObjectMethod(env,java_call,id_cancel);
if (cancel_result != NULL)
{
cancel_result_cstring = ConvertStringToCString((jobject)cancel_result);
elog(ERROR, "%s", cancel_result_cstring);
}
InterruptFlag = false;
elog(ERROR, "Query has been cancelled");
(*env)->ReleaseStringUTFChars(env, cancel_result, cancel_result_cstring);
(*env)->DeleteLocalRef(env, cancel_result);
}
}
/*
* ConvertStringToCString
* Uses a String object passed as a jobject to the function to
* create an instance of C String.
*/
static char*
ConvertStringToCString(jobject java_cstring)
{
jclass JavaString;
char *StringPointer;
SIGINTInterruptCheckProcess();
JavaString = (*env)->FindClass(env, "java/lang/String");
if (!((*env)->IsInstanceOf(env, java_cstring, JavaString)))
{
elog(ERROR, "Object not an instance of String class");
}
if (java_cstring != NULL)
{
StringPointer = (char*)(*env)->GetStringUTFChars(env, (jstring)java_cstring, 0);
}
else
{
StringPointer = NULL;
}
return (StringPointer);
}
/*
* DestroyJVM
* Shuts down the JVM.
*/
static void
DestroyJVM()
{
(*jvm)->DestroyJavaVM(jvm);
}
/*
* JVMInitialization
* Create the JVM which will be used for calling the Java routines
* that use JDBC to connect and access the foreign database.
*
*/
static void
JVMInitialization(Oid foreigntableid)
{
jint res = -5;/* Initializing the value of res so that we can check it later to see whether JVM has been correctly created or not*/
JavaVMInitArgs vm_args;
JavaVMOption *options;
static bool FunctionCallCheck = false; /* This flag safeguards against multiple calls of JVMInitialization().*/
char strpkglibdir[] = STR_PKGLIBDIR;
char *classpath;
char *svr_drivername = NULL;
char *svr_url = NULL;
char *svr_username = NULL;
char *svr_password = NULL;
char *svr_query = NULL;
char *svr_table = NULL;
char *svr_jarfile = NULL;
char *maxheapsizeoption = NULL;
int svr_querytimeout = 0;
int svr_maxheapsize = 0;
jdbcGetOptions(
foreigntableid,
&svr_drivername,
&svr_url,
&svr_querytimeout,
&svr_jarfile,
&svr_maxheapsize,
&svr_username,
&svr_password,
&svr_query,
&svr_table
);
SIGINTInterruptCheckProcess();
if (FunctionCallCheck == false)
{
classpath = (char*)palloc(strlen(strpkglibdir) + 19);
snprintf(classpath, strlen(strpkglibdir) + 19, "-Djava.class.path=%s", strpkglibdir);
if (svr_maxheapsize != 0) /* If the user has given a value for setting the max heap size of the JVM */
{
options = (JavaVMOption*)palloc(sizeof(JavaVMOption)*2);
maxheapsizeoption = (char*)palloc(sizeof(int) + 6);
snprintf(maxheapsizeoption, sizeof(int) + 6, "-Xmx%dm", svr_maxheapsize);
options[0].optionString = classpath;
options[1].optionString = maxheapsizeoption;
vm_args.nOptions = 2;
}
else
{
options = (JavaVMOption*)palloc(sizeof(JavaVMOption));
options[0].optionString = classpath;
vm_args.nOptions = 1;
}
vm_args.version = 0x00010002;
vm_args.options = options;
vm_args.ignoreUnrecognized = JNI_FALSE;
/* Create the Java VM */
res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
if (res < 0)
{
ereport(ERROR,
(errmsg("Failed to create Java VM")
));
}
InterruptFlag = false;
/* Register an on_proc_exit handler that shuts down the JVM.*/
on_proc_exit(DestroyJVM, 0);
FunctionCallCheck = true;
}
}
/*
* SIGINTInterruptHandler
* Handles SIGINT interrupt
*/
static void
SIGINTInterruptHandler(int sig)
{
InterruptFlag = true;
}
/*
* Foreign-data wrapper handler function: return a struct with pointers
* to my callback routines.
*/
Datum
jdbc_fdw_handler(PG_FUNCTION_ARGS)
{
FdwRoutine *fdwroutine = makeNode(FdwRoutine);
#if (PG_VERSION_NUM < 90200)
fdwroutine->PlanForeignScan = jdbcPlanForeignScan;
#endif
#if (PG_VERSION_NUM >= 90200)
fdwroutine->GetForeignRelSize = jdbcGetForeignRelSize;
fdwroutine->GetForeignPaths = jdbcGetForeignPaths;
fdwroutine->GetForeignPlan = jdbcGetForeignPlan;
#endif
fdwroutine->ExplainForeignScan = jdbcExplainForeignScan;
fdwroutine->BeginForeignScan = jdbcBeginForeignScan;
fdwroutine->IterateForeignScan = jdbcIterateForeignScan;
fdwroutine->ReScanForeignScan = jdbcReScanForeignScan;
fdwroutine->EndForeignScan = jdbcEndForeignScan;
pqsignal(SIGINT, SIGINTInterruptHandler);
PG_RETURN_POINTER(fdwroutine);
}
/*
* Validate the generic options given to a FOREIGN DATA WRAPPER, SERVER,
* USER MAPPING or FOREIGN TABLE that uses jdbc_fdw.
*
* Raise an ERROR if the option or its value is considered invalid.
*/
Datum
jdbc_fdw_validator(PG_FUNCTION_ARGS)
{
List *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
Oid catalog = PG_GETARG_OID(1);
char *svr_drivername = NULL;
char *svr_url = NULL;
char *svr_username = NULL;
char *svr_password = NULL;
char *svr_query = NULL;
char *svr_table = NULL;
char *svr_jarfile = NULL;
int svr_querytimeout = 0;
int svr_maxheapsize = 0;
ListCell *cell;
/*
* Check that only options supported by jdbc_fdw,
* and allowed for the current object type, are given.
*/
foreach(cell, options_list)
{
DefElem *def = (DefElem *) lfirst(cell);
if (!jdbcIsValidOption(def->defname, catalog))
{
struct jdbcFdwOption *opt;
StringInfoData buf;
/*
* Unknown option specified, complain about it. Provide a hint
* with list of valid options for the object.
*/
initStringInfo(&buf);
for (opt = valid_options; opt->optname; opt++)
{
if (catalog == opt->optcontext)
appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "",
opt->optname);
}
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
errmsg("invalid option \"%s\"", def->defname),
errhint("Valid options in this context are: %s", buf.len ? buf.data : "<none>")
));
}
if (strcmp(def->defname, "drivername") == 0)
{
if (svr_drivername)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: drivername (%s)", defGetString(def))
));
svr_drivername = defGetString(def);
}
if (strcmp(def->defname, "url") == 0)
{
if (svr_url)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: url (%s)", defGetString(def))
));
svr_url = defGetString(def);
}
if (strcmp(def->defname, "querytimeout") == 0)
{
if (svr_querytimeout)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: querytimeout (%s)", defGetString(def))
));
svr_querytimeout = atoi(defGetString(def));
}
if (strcmp(def->defname, "jarfile") == 0)
{
if (svr_jarfile)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: jarfile (%s)", defGetString(def))
));
svr_jarfile = defGetString(def);
}
if (strcmp(def->defname, "maxheapsize") == 0)
{
if (svr_maxheapsize)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: maxheapsize (%s)", defGetString(def))
));
svr_maxheapsize = atoi(defGetString(def));
}
if (strcmp(def->defname, "username") == 0)
{
if (svr_username)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: username (%s)", defGetString(def))
));
svr_username = defGetString(def);
}
if (strcmp(def->defname, "password") == 0)
{
if (svr_password)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: password (%s)", defGetString(def))
));
svr_password = defGetString(def);
}
else if (strcmp(def->defname, "query") == 0)
{
if (svr_table)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting options: query cannot be used with table")
));
if (svr_query)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: query (%s)", defGetString(def))
));
svr_query = defGetString(def);
}
else if (strcmp(def->defname, "table") == 0)
{
if (svr_query)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting options: table cannot be used with query")
));
if (svr_table)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options: table (%s)", defGetString(def))
));
svr_table = defGetString(def);
}
}
if (catalog == ForeignServerRelationId && svr_drivername == NULL)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("Driver name must be specified")
));
}
if (catalog == ForeignServerRelationId && svr_url == NULL)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("URL must be specified")
));
}
if (catalog == ForeignServerRelationId && svr_jarfile == NULL)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("JAR file must be specified")
));
}
if (catalog == ForeignTableRelationId && svr_query == NULL && svr_table == NULL)
{
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("either a table or a query must be specified")
));
}
PG_RETURN_VOID();
}
/*
* Check if the provided option is one of the valid options.
* context is the Oid of the catalog holding the object the option is for.
*/
static bool
jdbcIsValidOption(const char *option, Oid context)
{
struct jdbcFdwOption *opt;
for (opt = valid_options; opt->optname; opt++)
{
if (context == opt->optcontext && strcmp(opt->optname, option) == 0)
return true;
}
return false;
}
/*
* Fetch the options for a jdbc_fdw foreign table.
*/
static void
jdbcGetOptions(Oid foreigntableid, char **drivername, char **url, int *querytimeout, char **jarfile, int *maxheapsize, char **username, char **password, char **query, char **table)
{
ForeignTable *f_table;
ForeignServer *f_server;
UserMapping *f_mapping;
List *options;
ListCell *lc;
/*
* Extract options from FDW objects.
*/
f_table = GetForeignTable(foreigntableid);
f_server = GetForeignServer(f_table->serverid);
f_mapping = GetUserMapping(GetUserId(), f_table->serverid);
options = NIL;
options = list_concat(options, f_table->options);
options = list_concat(options, f_server->options);
options = list_concat(options, f_mapping->options);
/* Loop through the options, and get the server/port */
foreach(lc, options)
{
DefElem *def = (DefElem *) lfirst(lc);
if (strcmp(def->defname, "drivername") == 0)
{
*drivername = defGetString(def);
}
if (strcmp(def->defname, "username") == 0)
{
*username = defGetString(def);
}
if (strcmp(def->defname, "querytimeout") == 0)
{
*querytimeout = atoi(defGetString(def));
}
if (strcmp(def->defname, "jarfile") == 0)
{
*jarfile = defGetString(def);
}
if (strcmp(def->defname, "maxheapsize") == 0)
{
*maxheapsize = atoi(defGetString(def));
}
if (strcmp(def->defname, "password") == 0)
{
*password = defGetString(def);
}
if (strcmp(def->defname, "query") == 0)
{
*query = defGetString(def);
}
if (strcmp(def->defname, "table") == 0)
{
*table = defGetString(def);
}
if (strcmp(def->defname, "url") == 0)
{
*url = defGetString(def);
}
}
}
#if (PG_VERSION_NUM < 90200)
/*
* jdbcPlanForeignScan
* Create a FdwPlan for a scan on the foreign table
*/
static FdwPlan*
jdbcPlanForeignScan(Oid foreigntableid, PlannerInfo *root, RelOptInfo *baserel)
{
FdwPlan *fdwplan = NULL;
char *svr_drivername = NULL;
char *svr_username = NULL;
char *svr_password = NULL;
char *svr_query = NULL;
char *svr_table = NULL;
char *svr_url = NULL;
char *svr_jarfile = NULL;
int svr_querytimeout = 0;
int svr_maxheapsize = 0;
char *query;
SIGINTInterruptCheckProcess();
fdwplan = makeNode(FdwPlan);
JVMInitialization(foreigntableid);
/* Fetch options */
jdbcGetOptions(
foreigntableid,
&svr_drivername,
&svr_url,
&svr_querytimeout,
&svr_jarfile,
&svr_maxheapsize,
&svr_username,
&svr_password,
&svr_query,
&svr_table
);
/* Build the query */
if (svr_query)
{
size_t len = strlen(svr_query) + 9;
query = (char *) palloc(len);
snprintf(query, len, "EXPLAIN %s", svr_query);
}
else
{
size_t len = strlen(svr_table) + 23;
query = (char *) palloc(len);
snprintf(query, len, "EXPLAIN SELECT * FROM %s", svr_table);
}
return (fdwplan);
}
#endif
/*
* jdbcExplainForeignScan
* Produce extra output for EXPLAIN
*/
static void
jdbcExplainForeignScan(ForeignScanState *node, ExplainState *es)
{
char *svr_drivername = NULL;
char *svr_url = NULL;
char *svr_username = NULL;
char *svr_password = NULL;
char *svr_query = NULL;
char *svr_table = NULL;
char *svr_jarfile = NULL;
int svr_querytimeout = 0;
int svr_maxheapsize = 0;
/* Fetch options */
jdbcGetOptions(
RelationGetRelid(node->ss.ss_currentRelation),
&svr_drivername,
&svr_url,
&svr_querytimeout,
&svr_jarfile,
&svr_maxheapsize,
&svr_username,
&svr_password,
&svr_query,
&svr_table
);
SIGINTInterruptCheckProcess();
}
/*
* jdbcBeginForeignScan
* Initiate access to the database
*/
static void
jdbcBeginForeignScan(ForeignScanState *node, int eflags)
{
char *svr_drivername = NULL;
char *svr_url = NULL;
char *svr_username = NULL;
char *svr_password = NULL;
char *svr_query = NULL;
char *svr_table = NULL;
char *svr_jarfile = NULL;
int svr_querytimeout = 0;
int svr_maxheapsize = 0;
jdbcFdwExecutionState *festate;
char *query;
jclass JDBCUtilsClass;
jclass JavaString;
jstring StringArray[7];
jstring initialize_result = NULL;
jmethodID id_initialize;
jobjectArray arg_array;
int counter = 0;
int referencedeletecounter = 0;
jfieldID id_numberofcolumns;
char *querytimeoutstr = NULL;
char *jar_classpath;
char strpkglibdir[] = STR_PKGLIBDIR;
char *initialize_result_cstring = NULL;
SIGINTInterruptCheckProcess();
/* Fetch options */
jdbcGetOptions(
RelationGetRelid(node->ss.ss_currentRelation),
&svr_drivername,
&svr_url,
&svr_querytimeout,
&svr_jarfile,
&svr_maxheapsize,
&svr_username,
&svr_password,
&svr_query,
&svr_table
);
/* Build the query */
if (svr_query != NULL)
{
query = svr_query;
}
else
{
size_t len = strlen(svr_table) + 15;
query = (char *)palloc(len);
snprintf(query, len, "SELECT * FROM %s", svr_table);
}
/* Stash away the state info we have already */
festate = (jdbcFdwExecutionState *) palloc(sizeof(jdbcFdwExecutionState));
festate->query = query;
festate->NumberOfColumns = 0;
festate->NumberOfRows = 0;
/* Connect to the server and execute the query */
JDBCUtilsClass = (*env)->FindClass(env, "JDBCUtils");
if (JDBCUtilsClass == NULL)
{
elog(ERROR, "JDBCUtilsClass is NULL");
}
id_initialize = (*env)->GetMethodID(env, JDBCUtilsClass, "Initialize", "([Ljava/lang/String;)Ljava/lang/String;");
if (id_initialize == NULL)
{
elog(ERROR, "id_initialize is NULL");
}
id_numberofcolumns = (*env)->GetFieldID(env, JDBCUtilsClass, "NumberOfColumns" , "I");
if (id_numberofcolumns == NULL)
{
elog(ERROR, "id_numberofcolumns is NULL");
}
querytimeoutstr = (char*)palloc(sizeof(int));
jar_classpath = (char*)palloc(strlen(strpkglibdir) + strlen(svr_jarfile) + 2);
snprintf(querytimeoutstr, sizeof(int), "%d", svr_querytimeout);
snprintf(jar_classpath, (strlen(svr_jarfile) + 1), "%s", svr_jarfile);
if (svr_username == NULL)
{
svr_username = "";
}
if (svr_password == NULL)
{
svr_password = "";
}
StringArray[0] = (*env)->NewStringUTF(env, (festate->query));
StringArray[1] = (*env)->NewStringUTF(env, svr_drivername);
StringArray[2] = (*env)->NewStringUTF(env, svr_url);
StringArray[3] = (*env)->NewStringUTF(env, svr_username);
StringArray[4] = (*env)->NewStringUTF(env, svr_password);
StringArray[5] = (*env)->NewStringUTF(env, querytimeoutstr);
StringArray[6] = (*env)->NewStringUTF(env, jar_classpath);
JavaString = (*env)->FindClass(env, "java/lang/String");
arg_array = (*env)->NewObjectArray(env, 7, JavaString, StringArray[0]);
if (arg_array == NULL)
{
elog(ERROR, "arg_array is NULL");
}
for (counter = 1; counter < 7; counter++)
{
(*env)->SetObjectArrayElement(env, arg_array, counter, StringArray[counter]);
}
java_call = (*env)->AllocObject(env, JDBCUtilsClass);
if (java_call == NULL)
{
elog(ERROR, "java_call is NULL");
}
festate->java_call = java_call;
initialize_result = (*env)->CallObjectMethod(env, java_call, id_initialize, arg_array);
if (initialize_result != NULL)
{
initialize_result_cstring = ConvertStringToCString((jobject)initialize_result);
elog(ERROR, "%s", initialize_result_cstring);
}
node->fdw_state = (void *) festate;
festate->NumberOfColumns = (*env)->GetIntField(env, java_call, id_numberofcolumns);
for (referencedeletecounter = 0; referencedeletecounter < 7; referencedeletecounter++)
{
(*env)->DeleteLocalRef(env, StringArray[referencedeletecounter]);
}
(*env)->DeleteLocalRef(env, arg_array);
(*env)->ReleaseStringUTFChars(env, initialize_result, initialize_result_cstring);
(*env)->DeleteLocalRef(env, initialize_result);
}
/*
* jdbcIterateForeignScan
* Read next record from the data file and store it into the
* ScanTupleSlot as a virtual tuple
*/
static TupleTableSlot*
jdbcIterateForeignScan(ForeignScanState *node)
{
char **values;
HeapTuple tuple;
jmethodID id_returnresultset;
jclass JDBCUtilsClass;
jobjectArray java_rowarray;
int i = 0;
int j = 0;
jstring tempString;
jdbcFdwExecutionState *festate = (jdbcFdwExecutionState *) node->fdw_state;
TupleTableSlot *slot = node->ss.ss_ScanTupleSlot;
jobject java_call = festate->java_call;
/* Cleanup */
ExecClearTuple(slot);
SIGINTInterruptCheckProcess();
if ((*env)->PushLocalFrame(env, (festate->NumberOfColumns + 10)) < 0)
{
/* frame not pushed, no PopLocalFrame needed */
elog(ERROR, "Error");
}
JDBCUtilsClass = (*env)->FindClass(env, "JDBCUtils");
if (JDBCUtilsClass == NULL)
{
elog(ERROR, "JDBCUtilsClass is NULL");
}
id_returnresultset = (*env)->GetMethodID(env, JDBCUtilsClass, "ReturnResultSet", "()[Ljava/lang/String;");
if (id_returnresultset == NULL)
{
elog(ERROR, "id_returnresultset is NULL");
}
values=(char**)palloc(sizeof(char*)*(festate->NumberOfColumns));
java_rowarray = (*env)->CallObjectMethod(env, java_call, id_returnresultset);
if (java_rowarray != NULL)
{
for (i = 0; i < (festate->NumberOfColumns); i++)
{
values[i] = ConvertStringToCString((jobject)(*env)->GetObjectArrayElement(env, java_rowarray, i));
}
tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(node->ss.ss_currentRelation->rd_att), values);
ExecStoreTuple(tuple, slot, InvalidBuffer, false);
++ (festate->NumberOfRows);
for (j = 0; j < festate->NumberOfColumns; j++)
{
tempString = (jstring)(*env)->GetObjectArrayElement(env, java_rowarray,j);
(*env)->ReleaseStringUTFChars(env, tempString, values[j]);
(*env)->DeleteLocalRef(env, tempString);
}
(*env)->DeleteLocalRef(env, java_rowarray);
}
(*env)->PopLocalFrame(env, NULL);
return (slot);
}
/*
* jdbcEndForeignScan