mongo_fdw.h

/*-------------------------------------------------------------------------
 *
 * mongo_fdw.h
 * 		Foreign-data wrapper for remote MongoDB servers
 *
 * Portions Copyright (c) 2012-2014, PostgreSQL Global Development Group
 *
 * Portions Copyright (c) 2004-2014, EnterpriseDB Corporation.
 *
 * Portions Copyright (c) 2012–2014 Citus Data, Inc.
 *
 * IDENTIFICATION
 * 		mongo_fdw.h
 *
 *-------------------------------------------------------------------------
 */

#ifndef MONGO_FDW_H
#define MONGO_FDW_H

#include "config.h"
#include "mongo_wrapper.h"
#include "bson.h"

#ifdef META_DRIVER
	#include "mongoc.h"
#else
	#include "mongo.h"
#endif

#include "fmgr.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_foreign_table.h"
#include "utils/datetime.h"
#include "nodes/pg_list.h"
#if PG_VERSION_NUM < 120000
	#include "nodes/relation.h"
#endif
#include "utils/timestamp.h"
#include "access/reloptions.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "commands/vacuum.h"
#include "foreign/fdwapi.h"
#include "foreign/foreign.h"
#include "nodes/makefuncs.h"
#include "optimizer/cost.h"
#include "optimizer/pathnode.h"
#include "optimizer/plancat.h"
#include "optimizer/planmain.h"
#include "optimizer/restrictinfo.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/hsearch.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/memutils.h"
#include "catalog/pg_user_mapping.h"

#ifdef META_DRIVER
	#define BSON bson_t
	#define BSON_TYPE bson_type_t
	#define BSON_ITERATOR bson_iter_t
	#define MONGO_CONN mongoc_client_t
	#define MONGO_CURSOR mongoc_cursor_t
	#define BSON_TYPE_DOCUMENT BSON_TYPE_DOCUMENT
	#define BSON_TYPE_NULL BSON_TYPE_NULL
	#define BSON_TYPE_ARRAY BSON_TYPE_ARRAY
	#define BSON_TYPE_INT32 BSON_TYPE_INT32
	#define BSON_TYPE_INT64 BSON_TYPE_INT64
	#define BSON_TYPE_DOUBLE BSON_TYPE_DOUBLE
	#define BSON_TYPE_BINDATA BSON_TYPE_BINARY
	#define BSON_TYPE_BOOL BSON_TYPE_BOOL
	#define BSON_TYPE_UTF8 BSON_TYPE_UTF8
	#define BSON_TYPE_OID BSON_TYPE_OID
	#define BSON_TYPE_DATE_TIME BSON_TYPE_DATE_TIME
	#define BSON_TYPE_SYMBOL BSON_TYPE_SYMBOL
	#define BSON_TYPE_UNDEFINED BSON_TYPE_UNDEFINED
	#define BSON_TYPE_REGEX BSON_TYPE_REGEX
	#define BSON_TYPE_CODE BSON_TYPE_CODE
	#define BSON_TYPE_CODEWSCOPE BSON_TYPE_CODEWSCOPE
	#define BSON_TYPE_TIMESTAMP BSON_TYPE_TIMESTAMP

	#define PREF_READ_PRIMARY_NAME "readPrimary"
	#define PREF_READ_SECONDARY_NAME "readSecondary"
	#define PREF_READ_PRIMARY_PREFERRED_NAME "readPrimaryPreferred"
	#define PREF_READ_SECONDARY_PREFERRED_NAME "readSecondaryPreferred"
	#define PREF_READ_NEAREST_NAME "readNearest"

	#define BSON_ITER_BOOL bson_iter_bool
	#define BSON_ITER_DOUBLE bson_iter_double
	#define BSON_ITER_INT32 bson_iter_int32
	#define BSON_ITER_INT64 bson_iter_int64
	#define BSON_ITER_OID bson_iter_oid
	#define BSON_ITER_UTF8 bson_iter_utf8
	#define BSON_ITER_REGEX bson_iter_regex
	#define BSON_ITER_DATE_TIME bson_iter_date_time
	#define BSON_ITER_CODE bson_iter_code
	#define BSON_ITER_VALUE bson_iter_value
	#define BSON_ITER_KEY bson_iter_key
	#define BSON_ITER_NEXT bson_iter_next
	#define BSON_ITER_TYPE bson_iter_type
	#define BSON_ITER_BINARY bson_iter_binary
#else
	#define BSON bson
	#define BSON_TYPE bson_type
	#define BSON_ITERATOR bson_iterator
	#define MONGO_CONN mongo
	#define MONGO_CURSOR mongo_cursor
	#define BSON_TYPE_DOCUMENT BSON_OBJECT
	#define BSON_TYPE_NULL BSON_NULL
	#define BSON_TYPE_ARRAY BSON_ARRAY
	#define BSON_TYPE_INT32 BSON_INT
	#define BSON_TYPE_INT64 BSON_LONG
	#define BSON_TYPE_DOUBLE BSON_DOUBLE
	#define BSON_TYPE_BINDATA BSON_BINDATA
	#define BSON_TYPE_BOOL BSON_BOOL
	#define BSON_TYPE_UTF8 BSON_STRING
	#define BSON_TYPE_OID BSON_OID
	#define BSON_TYPE_DATE_TIME BSON_DATE
	#define BSON_TYPE_SYMBOL BSON_SYMBOL
	#define BSON_TYPE_UNDEFINED BSON_UNDEFINED
	#define BSON_TYPE_REGEX BSON_REGEX
	#define BSON_TYPE_CODE BSON_CODE
	#define BSON_TYPE_CODEWSCOPE BSON_CODEWSCOPE
	#define BSON_TYPE_TIMESTAMP BSON_TIMESTAMP

	#define BSON_ITER_BOOL bson_iterator_bool
	#define BSON_ITER_DOUBLE bson_iterator_double
	#define BSON_ITER_INT32 bson_iterator_int
	#define BSON_ITER_INT64 bson_iterator_long
	#define BSON_ITER_OID bson_iterator_oid
	#define BSON_ITER_UTF8 bson_iterator_string
	#define BSON_ITER_REGEX bson_iterator_regex
	#define BSON_ITER_DATE_TIME bson_iterator_date
	#define BSON_ITER_CODE bson_iterator_code
	#define BSON_ITER_VALUE bson_iterator_value
	#define BSON_ITER_KEY bson_iterator_key
	#define BSON_ITER_NEXT bson_iterator_next
	#define BSON_ITER_TYPE bson_iterator_type
	#define BSON_ITER_BINARY bson_iterator_bin_data
#endif

/* Defines for valid option names */
#define OPTION_NAME_ADDRESS "address"
#define OPTION_NAME_PORT "port"
#define OPTION_NAME_DATABASE "database"
#define OPTION_NAME_COLLECTION "collection"
#define OPTION_NAME_USERNAME "username"
#define OPTION_NAME_PASSWORD "password"
#ifdef META_DRIVER
#define OPTION_NAME_READ_PREFERENCE "read_preference"
#define OPTION_NAME_AUTHENTICATION_DATABASE "authentication_database"
#define OPTION_NAME_REPLICA_SET "replica_set"
#define OPTION_NAME_SSL "ssl"
#define OPTION_NAME_PEM_FILE "pem_file"
#define OPTION_NAME_PEM_PWD "pem_pwd"
#define OPTION_NAME_CA_FILE "ca_file"
#define OPTION_NAME_CA_DIR "ca_dir"
#define OPTION_NAME_CRL_FILE "crl_file"
#define OPTION_NAME_WEAK_CERT "weak_cert_validation"
#endif

/* Default values for option parameters */
#define DEFAULT_IP_ADDRESS "127.0.0.1"
#define DEFAULT_PORT_NUMBER 27017
#define DEFAULT_DATABASE_NAME "test"

/* Defines for sending queries and converting types */
#define EQUALITY_OPERATOR_NAME "="
#define INITIAL_ARRAY_CAPACITY 8
#define MONGO_TUPLE_COST_MULTIPLIER 5
#define MONGO_CONNECTION_COST_MULTIPLIER 5
#define POSTGRES_TO_UNIX_EPOCH_DAYS (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE)
#define POSTGRES_TO_UNIX_EPOCH_USECS (POSTGRES_TO_UNIX_EPOCH_DAYS * USECS_PER_DAY)


/*
 * MongoValidOption keeps an option name and a context. When an option is passed
 * into mongo_fdw objects (server and foreign table), we compare this option's
 * name and context against those of valid options.
 */
typedef struct MongoValidOption
{
	const char *optionName;
	Oid optionContextId;

} MongoValidOption;


/* Array of options that are valid for mongo_fdw */
#ifdef META_DRIVER
static const uint32 ValidOptionCount = 16;
#else
static const uint32 ValidOptionCount = 6;
#endif
static const MongoValidOption ValidOptionArray[] =
{
	/* foreign server options */
	{ OPTION_NAME_ADDRESS, ForeignServerRelationId },
	{ OPTION_NAME_PORT, ForeignServerRelationId },

#ifdef META_DRIVER
	{ OPTION_NAME_READ_PREFERENCE, ForeignServerRelationId },
	{ OPTION_NAME_AUTHENTICATION_DATABASE, ForeignServerRelationId },
	{ OPTION_NAME_REPLICA_SET, ForeignServerRelationId },
	{ OPTION_NAME_SSL, ForeignServerRelationId },
	{ OPTION_NAME_PEM_FILE, ForeignServerRelationId },
	{ OPTION_NAME_PEM_PWD, ForeignServerRelationId },
	{ OPTION_NAME_CA_FILE, ForeignServerRelationId },
	{ OPTION_NAME_CA_DIR, ForeignServerRelationId },
	{ OPTION_NAME_CRL_FILE, ForeignServerRelationId },
	{ OPTION_NAME_WEAK_CERT, ForeignServerRelationId },
#endif

	/* foreign table options */
	{ OPTION_NAME_DATABASE, ForeignTableRelationId },
	{ OPTION_NAME_COLLECTION, ForeignTableRelationId },

	/* User mapping options */
	{ OPTION_NAME_USERNAME, UserMappingRelationId },
	{ OPTION_NAME_PASSWORD, UserMappingRelationId }

};


/*
 * MongoFdwOptions holds the option values to be used when connecting to Mongo.
 * To resolve these values, we first check foreign table's options, and if not
 * present, we then fall back to the default values specified above.
 */
typedef struct MongoFdwOptions
{
	char *svr_address;
	int32 svr_port;
	char *svr_database;
	char *collectionName;
	char *svr_username;
	char *svr_password;
#ifdef META_DRIVER
	char *readPreference;
	char *authenticationDatabase;
	char *replicaSet;
 	bool ssl;
	char *pem_file;
 	char *pem_pwd;
 	char *ca_file;
 	char *ca_dir;
 	char *crl_file;
 	bool weak_cert_validation;
#endif
} MongoFdwOptions;


/*
 * MongoFdwExecState keeps foreign data wrapper specific execution state that we
 * create and hold onto when executing the query.
 */
/*
 * Execution state of a foreign insert/update/delete operation.
 */
typedef struct MongoFdwModifyState
{
	Relation		rel;				/* relcache entry for the foreign table */
	List			*target_attrs;		/* list of target attribute numbers */

	/* info about parameters for prepared statement */
	int				p_nums;				/* number of parameters to transmit */
	FmgrInfo		*p_flinfo;			/* output conversion functions for them */

	struct HTAB		*columnMappingHash;

	MONGO_CONN		*mongoConnection;	/* MongoDB connection */
	MONGO_CURSOR	*mongoCursor;		/* MongoDB cursor */
	BSON			*queryDocument;		/* Bson Document */

	MongoFdwOptions	*options;

	/* working memory context */
	MemoryContext	temp_cxt;			/* context for per-tuple temporary data */
} MongoFdwModifyState;


/*
 * ColumnMapping reprents a hash table entry that maps a column name to column
 * related information. We construct these hash table entries to speed up the
 * conversion from BSON documents to PostgreSQL tuples; and each hash entry maps
 * the column name to the column's tuple index and its type-related information.
 */
typedef struct ColumnMapping
{
	char columnName[NAMEDATALEN];
	uint32 columnIndex;
	Oid columnTypeId;
	int32 columnTypeMod;
	Oid columnArrayTypeId;
} ColumnMapping;

/* options.c */
extern MongoFdwOptions * mongo_get_options(Oid foreignTableId);
extern void mongo_free_options(MongoFdwOptions *options);
extern StringInfo mongo_option_names_string(Oid currentContextId);

/* connection.c */
MONGO_CONN* mongo_get_connection(ForeignServer *server, UserMapping *user, MongoFdwOptions *opt);

extern void mongo_cleanup_connection(void);
extern void mongo_release_connection(MONGO_CONN* conn);

/* Function declarations related to creating the mongo query */
extern List * ApplicableOpExpressionList(RelOptInfo *baserel);
extern BSON * QueryDocument(Oid relationId, List *opExpressionList,
				ForeignScanState *scanStateNode);
extern List * ColumnList(RelOptInfo *baserel);

/* Function declarations for foreign data wrapper */
extern Datum mongo_fdw_handler(PG_FUNCTION_ARGS);
extern Datum mongo_fdw_validator(PG_FUNCTION_ARGS);


#endif   /* MONGO_FDW_H */