keywords.go

/*
Copyright 2021 The Vitess Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package sqlparser

import (
	"fmt"
	"strings"
)

type keyword struct {
	name string
	id   int
}

func (k *keyword) match(input []byte) bool {
	if len(input) != len(k.name) {
		return false
	}
	for i, c := range input {
		if 'A' <= c && c <= 'Z' {
			c += 'a' - 'A'
		}
		if k.name[i] != c {
			return false
		}
	}
	return true
}

func (k *keyword) matchStr(input string) bool {
	return keywordASCIIMatch(input, k.name)
}

func keywordASCIIMatch(input string, expected string) bool {
	if len(input) != len(expected) {
		return false
	}
	for i := 0; i < len(input); i++ {
		c := input[i]
		if 'A' <= c && c <= 'Z' {
			c += 'a' - 'A'
		}
		if expected[i] != c {
			return false
		}
	}
	return true
}

// keywords is a table of mysql keywords that fall into two categories:
// 1) keywords considered reserved by MySQL
// 2) keywords for us to handle specially in sql.y
//
// Those marked as UNUSED are likely reserved keywords. We add them here so that
// when rewriting queries we can properly backtick quote them so they don't cause issues
//
// NOTE: If you add new keywords, add them also to the reserved_keywords or
// non_reserved_keywords grammar in sql.y -- this will allow the keyword to be used
// in identifiers. See the docs for each grammar to determine which one to put it into.
var keywords = []keyword{
	{"_armscii8", UNDERSCORE_ARMSCII8},
	{"_ascii", UNDERSCORE_ASCII},
	{"_big5", UNDERSCORE_BIG5},
	{"_binary", UNDERSCORE_BINARY},
	{"_cp1250", UNDERSCORE_CP1250},
	{"_cp1251", UNDERSCORE_CP1251},
	{"_cp1256", UNDERSCORE_CP1256},
	{"_cp1257", UNDERSCORE_CP1257},
	{"_cp850", UNDERSCORE_CP850},
	{"_cp852", UNDERSCORE_CP852},
	{"_cp866", UNDERSCORE_CP866},
	{"_cp932", UNDERSCORE_CP932},
	{"_dec8", UNDERSCORE_DEC8},
	{"_eucjpms", UNDERSCORE_EUCJPMS},
	{"_euckr", UNDERSCORE_EUCKR},
	{"_gb18030", UNDERSCORE_GB18030},
	{"_gb2312", UNDERSCORE_GB2312},
	{"_gbk", UNDERSCORE_GBK},
	{"_geostd8", UNDERSCORE_GEOSTD8},
	{"_greek", UNDERSCORE_GREEK},
	{"_hebrew", UNDERSCORE_HEBREW},
	{"_hp8", UNDERSCORE_HP8},
	{"_keybcs2", UNDERSCORE_KEYBCS2},
	{"_koi8r", UNDERSCORE_KOI8R},
	{"_koi8u", UNDERSCORE_KOI8U},
	{"_latin1", UNDERSCORE_LATIN1},
	{"_latin2", UNDERSCORE_LATIN2},
	{"_latin5", UNDERSCORE_LATIN5},
	{"_latin7", UNDERSCORE_LATIN7},
	{"_macce", UNDERSCORE_MACCE},
	{"_macroman", UNDERSCORE_MACROMAN},
	{"_sjis", UNDERSCORE_SJIS},
	{"_swe7", UNDERSCORE_SWE7},
	{"_tis620", UNDERSCORE_TIS620},
	{"_ucs2", UNDERSCORE_UCS2},
	{"_ujis", UNDERSCORE_UJIS},
	{"_utf16", UNDERSCORE_UTF16},
	{"_utf16le", UNDERSCORE_UTF16LE},
	{"_utf32", UNDERSCORE_UTF32},
	{"_utf8", UNDERSCORE_UTF8},
	{"_utf8mb4", UNDERSCORE_UTF8MB4},
	{"_utf8mb3", UNDERSCORE_UTF8MB3},
	{"accessible", UNUSED},
	{"action", ACTION},
	{"add", ADD},
	{"adddate", ADDDATE},
	{"after", AFTER},
	{"against", AGAINST},
	{"algorithm", ALGORITHM},
	{"all", ALL},
	{"alter", ALTER},
	{"always", ALWAYS},
	{"analyze", ANALYZE},
	{"and", AND},
	{"any_value", ANY_VALUE},
	{"array", ARRAY},
	{"as", AS},
	{"asc", ASC},
	{"ascii", ASCII},
	{"asensitive", UNUSED},
	{"auto_increment", AUTO_INCREMENT},
	{"autoextend_size", AUTOEXTEND_SIZE},
	{"avg", AVG},
	{"avg_row_length", AVG_ROW_LENGTH},
	{"before", BEFORE},
	{"begin", BEGIN},
	{"between", BETWEEN},
	{"bigint", BIGINT},
	{"binary", BINARY},
	{"bit", BIT},
	{"bit_and", BIT_AND},
	{"bit_or", BIT_OR},
	{"bit_xor", BIT_XOR},
	{"blob", BLOB},
	{"bool", BOOL},
	{"boolean", BOOLEAN},
	{"both", BOTH},
	{"by", BY},
	{"byte", BYTE},
	{"call", CALL},
	{"cancel", CANCEL},
	{"cascade", CASCADE},
	{"cascaded", CASCADED},
	{"case", CASE},
	{"cast", CAST},
	{"channel", CHANNEL},
	{"change", CHANGE},
	{"char", CHAR},
	{"character", CHARACTER},
	{"charset", CHARSET},
	{"check", CHECK},
	{"checksum", CHECKSUM},
	{"cleanup", CLEANUP},
	{"coalesce", COALESCE},
	{"code", CODE},
	{"collate", COLLATE},
	{"collation", COLLATION},
	{"column", COLUMN},
	{"column_format", COLUMN_FORMAT},
	{"columns", COLUMNS},
	{"comment", COMMENT_KEYWORD},
	{"committed", COMMITTED},
	{"commit", COMMIT},
	{"compact", COMPACT},
	{"complete", COMPLETE},
	{"compressed", COMPRESSED},
	{"compression", COMPRESSION},
	{"condition", UNUSED},
	{"connection", CONNECTION},
	{"consistent", CONSISTENT},
	{"constraint", CONSTRAINT},
	{"continue", UNUSED},
	{"convert", CONVERT},
	{"copy", COPY},
	{"count", COUNT},
	{"cume_dist", CUME_DIST},
	{"substr", SUBSTRING},
	{"subpartition", SUBPARTITION},
	{"subpartitions", SUBPARTITIONS},
	{"substring", SUBSTRING},
	{"srid", SRID},
	{"create", CREATE},
	{"cross", CROSS},
	{"csv", CSV},
	{"current", CURRENT},
	{"current_date", CURRENT_DATE},
	{"curdate", CURDATE},
	{"current_time", CURRENT_TIME},
	{"curtime", CURTIME},
	{"current_timestamp", CURRENT_TIMESTAMP},
	{"current_user", CURRENT_USER},
	{"cursor", UNUSED},
	{"data", DATA},
	{"database", DATABASE},
	{"databases", DATABASES},
	{"day", DAY},
	{"day_hour", DAY_HOUR},
	{"day_microsecond", DAY_MICROSECOND},
	{"day_minute", DAY_MINUTE},
	{"day_second", DAY_SECOND},
	{"date", DATE},
	{"datetime", DATETIME},
	{"date_add", DATE_ADD},
	{"date_sub", DATE_SUB},
	{"deallocate", DEALLOCATE},
	{"dec", UNUSED},
	{"decimal", DECIMAL_TYPE},
	{"declare", UNUSED},
	{"default", DEFAULT},
	{"definer", DEFINER},
	{"delay_key_write", DELAY_KEY_WRITE},
	{"delayed", UNUSED},
	{"delete", DELETE},
	{"dense_rank", DENSE_RANK},
	{"desc", DESC},
	{"describe", DESCRIBE},
	{"deterministic", UNUSED},
	{"directory", DIRECTORY},
	{"disable", DISABLE},
	{"discard", DISCARD},
	{"disk", DISK},
	{"distinct", DISTINCT},
	{"distinctrow", DISTINCTROW},
	{"div", DIV},
	{"double", DOUBLE},
	{"do", DO},
	{"drop", DROP},
	{"dumpfile", DUMPFILE},
	{"duplicate", DUPLICATE},
	{"dynamic", DYNAMIC},
	{"each", UNUSED},
	{"else", ELSE},
	{"elseif", UNUSED},
	{"empty", EMPTY},
	{"enable", ENABLE},
	{"enclosed", ENCLOSED},
	{"encryption", ENCRYPTION},
	{"end", END},
	{"endpoint", ST_EndPoint},
	{"enforced", ENFORCED},
	{"engine", ENGINE},
	{"engine_attribute", ENGINE_ATTRIBUTE},
	{"engines", ENGINES},
	{"enum", ENUM},
	{"error", ERROR},
	{"escape", ESCAPE},
	{"escaped", ESCAPED},
	{"event", EVENT},
	{"exchange", EXCHANGE},
	{"exclusive", EXCLUSIVE},
	{"execute", EXECUTE},
	{"exists", EXISTS},
	{"exit", UNUSED},
	{"explain", EXPLAIN},
	{"expansion", EXPANSION},
	{"expire", EXPIRE},
	{"export", EXPORT},
	{"extended", EXTENDED},
	{"extract", EXTRACT},
	{"extractvalue", ExtractValue},
	{"false", FALSE},
	{"fetch", UNUSED},
	{"fields", FIELDS},
	{"first", FIRST},
	{"first_value", FIRST_VALUE},
	{"fixed", FIXED},
	{"float", FLOAT_TYPE},
	{"float4", FLOAT4_TYPE},
	{"float8", FLOAT8_TYPE},
	{"flush", FLUSH},
	{"following", FOLLOWING},
	{"for", FOR},
	{"force", FORCE},
	{"force_cutover", FORCE_CUTOVER},
	{"foreign", FOREIGN},
	{"format", FORMAT},
	{"format_bytes", FORMAT_BYTES},
	{"format_pico_time", FORMAT_PICO_TIME},
	{"from", FROM},
	{"full", FULL},
	{"fulltext", FULLTEXT},
	{"function", FUNCTION},
	{"general", GENERAL},
	{"generated", GENERATED},
	{"geometry", GEOMETRY},
	{"geomcollection", GEOMETRYCOLLECTION},
	{"geometrycollection", GEOMETRYCOLLECTION},
	{"get", UNUSED},
	{"get_lock", GET_LOCK},
	{"glength", ST_Length},
	{"global", GLOBAL},
	{"gtid_executed", GTID_EXECUTED},
	{"gtid_subset", GTID_SUBSET},
	{"gtid_subtract", GTID_SUBTRACT},
	{"grant", UNUSED},
	{"group", GROUP},
	{"grouping", UNUSED},
	{"groups", UNUSED},
	{"group_concat", GROUP_CONCAT},
	{"hash", HASH},
	{"having", HAVING},
	{"header", HEADER},
	{"high_priority", UNUSED},
	{"hosts", HOSTS},
	{"hour", HOUR},
	{"hour_microsecond", HOUR_MICROSECOND},
	{"hour_minute", HOUR_MINUTE},
	{"hour_second", HOUR_SECOND},
	{"if", IF},
	{"ignore", IGNORE},
	{"import", IMPORT},
	{"in", IN},
	{"index", INDEX},
	{"indexes", INDEXES},
	{"infile", UNUSED},
	{"inout", UNUSED},
	{"inner", INNER},
	{"inplace", INPLACE},
	{"insensitive", UNUSED},
	{"insert", INSERT},
	{"insert_method", INSERT_METHOD},
	{"instant", INSTANT},
	{"invisible", INVISIBLE},
	{"int", INT},
	{"int1", UNUSED},
	{"int2", UNUSED},
	{"int3", UNUSED},
	{"int4", UNUSED},
	{"int8", UNUSED},
	{"integer", INTEGER},
	{"interval", INTERVAL},
	{"into", INTO},
	{"io_after_gtids", UNUSED},
	{"is", IS},
	{"isclosed", ST_IsClosed},
	{"is_free_lock", IS_FREE_LOCK},
	{"is_used_lock", IS_USED_LOCK},
	{"isolation", ISOLATION},
	{"iterate", UNUSED},
	{"invoker", INVOKER},
	{"join", JOIN},
	{"json", JSON},
	{"json_array", JSON_ARRAY},
	{"json_array_append", JSON_ARRAY_APPEND},
	{"json_array_insert", JSON_ARRAY_INSERT},
	{"json_contains", JSON_CONTAINS},
	{"json_contains_path", JSON_CONTAINS_PATH},
	{"json_depth", JSON_DEPTH},
	{"json_extract", JSON_EXTRACT},
	{"json_insert", JSON_INSERT},
	{"json_length", JSON_LENGTH},
	{"json_keys", JSON_KEYS},
	{"json_merge", JSON_MERGE},
	{"json_merge_patch", JSON_MERGE_PATCH},
	{"json_merge_preserve", JSON_MERGE_PRESERVE},
	{"json_object", JSON_OBJECT},
	{"json_overlaps", JSON_OVERLAPS},
	{"json_pretty", JSON_PRETTY},
	{"json_remove", JSON_REMOVE},
	{"json_replace", JSON_REPLACE},
	{"json_search", JSON_SEARCH},
	{"json_schema_valid", JSON_SCHEMA_VALID},
	{"json_schema_validation_report", JSON_SCHEMA_VALIDATION_REPORT},
	{"json_set", JSON_SET},
	{"json_storage_free", JSON_STORAGE_FREE},
	{"json_storage_size", JSON_STORAGE_SIZE},
	{"json_quote", JSON_QUOTE},
	{"json_table", JSON_TABLE},
	{"json_type", JSON_TYPE},
	{"json_value", JSON_VALUE},
	{"json_valid", JSON_VALID},
	{"json_unquote", JSON_UNQUOTE},
	{"key", KEY},
	{"keys", KEYS},
	{"keyspaces", KEYSPACES},
	{"key_block_size", KEY_BLOCK_SIZE},
	{"kill", KILL},
	{"lag", LAG},
	{"language", LANGUAGE},
	{"last", LAST},
	{"last_value", LAST_VALUE},
	{"last_insert_id", LAST_INSERT_ID},
	{"lateral", LATERAL},
	{"launch", LAUNCH},
	{"lead", LEAD},
	{"leading", LEADING},
	{"leave", UNUSED},
	{"left", LEFT},
	{"less", LESS},
	{"level", LEVEL},
	{"like", LIKE},
	{"limit", LIMIT},
	{"linear", LINEAR},
	{"lines", LINES},
	{"linestring", LINESTRING},
	{"list", LIST},
	{"load", LOAD},
	{"local", LOCAL},
	{"localtime", LOCALTIME},
	{"localtimestamp", LOCALTIMESTAMP},
	{"locate", LOCATE},
	{"lock", LOCK},
	{"locked", LOCKED},
	{"logs", LOGS},
	{"long", UNUSED},
	{"longblob", LONGBLOB},
	{"longtext", LONGTEXT},
	{"loop", UNUSED},
	{"low_priority", LOW_PRIORITY},
	{"ltrim", LTRIM},
	{"mid", MID},
	{"min", MIN},
	{"manifest", MANIFEST},
	{"master_bind", UNUSED},
	{"match", MATCH},
	{"max", MAX},
	{"max_rows", MAX_ROWS},
	{"maxvalue", MAXVALUE},
	{"mediumblob", MEDIUMBLOB},
	{"mediumint", MEDIUMINT},
	{"mediumtext", MEDIUMTEXT},
	{"memory", MEMORY},
	{"member", MEMBER},
	{"merge", MERGE},
	{"microsecond", MICROSECOND},
	{"middleint", UNUSED},
	{"min_rows", MIN_ROWS},
	{"minute", MINUTE},
	{"minute_microsecond", MINUTE_MICROSECOND},
	{"minute_second", MINUTE_SECOND},
	{"mod", MOD},
	{"mode", MODE},
	{"modify", MODIFY},
	{"modifies", UNUSED},
	{"multilinestring", MULTILINESTRING},
	{"multipoint", MULTIPOINT},
	{"multipolygon", MULTIPOLYGON},
	{"month", MONTH},
	{"name", NAME},
	{"names", NAMES},
	{"natural", NATURAL},
	{"nchar", NCHAR},
	{"next", NEXT},
	{"nested", NESTED},
	{"no", NO},
	{"none", NONE},
	{"not", NOT},
	{"now", NOW},
	{"nowait", NOWAIT},
	{"no_write_to_binlog", NO_WRITE_TO_BINLOG},
	{"nth_value", NTH_VALUE},
	{"ntile", NTILE},
	{"null", NULL},
	{"nulls", NULLS},
	{"numeric", NUMERIC},
	{"numpoints", ST_NumPoints},
	{"of", OF},
	{"off", OFF},
	{"offset", OFFSET},
	{"on", ON},
	{"only", ONLY},
	{"open", OPEN},
	{"optimize", OPTIMIZE},
	{"optimizer_costs", OPTIMIZER_COSTS},
	{"option", OPTION},
	{"optionally", OPTIONALLY},
	{"or", OR},
	{"order", ORDER},
	{"ordinality", ORDINALITY},
	{"out", UNUSED},
	{"outer", OUTER},
	{"outfile", OUTFILE},
	{"over", OVER},
	{"overwrite", OVERWRITE},
	{"pack_keys", PACK_KEYS},
	{"parser", PARSER},
	{"partial", PARTIAL},
	{"partition", PARTITION},
	{"partitions", PARTITIONS},
	{"partitioning", PARTITIONING},
	{"password", PASSWORD},
	{"path", PATH},
	{"percent_rank", PERCENT_RANK},
	{"plan", PLAN},
	{"plugins", PLUGINS},
	{"point", POINT},
	{"pointn", ST_PointN},
	{"polygon", POLYGON},
	{"position", POSITION},
	{"preceding", PRECEDING},
	{"precision", UNUSED},
	{"prepare", PREPARE},
	{"primary", PRIMARY},
	{"privileges", PRIVILEGES},
	{"purge", PURGE},
	{"processlist", PROCESSLIST},
	{"procedure", PROCEDURE},
	{"ps_current_thread_id", PS_CURRENT_THREAD_ID},
	{"ps_thread_id", PS_THREAD_ID},
	{"queries", QUERIES},
	{"query", QUERY},
	{"range", RANGE},
	{"quarter", QUARTER},
	{"rank", RANK},
	{"ratio", RATIO},
	{"read", READ},
	{"reads", UNUSED},
	{"read_write", UNUSED},
	{"real", REAL},
	{"rebuild", REBUILD},
	{"recursive", RECURSIVE},
	{"redundant", REDUNDANT},
	{"references", REFERENCES},
	{"regexp", REGEXP},
	{"regexp_instr", REGEXP_INSTR},
	{"regexp_like", REGEXP_LIKE},
	{"regexp_replace", REGEXP_REPLACE},
	{"regexp_substr", REGEXP_SUBSTR},
	{"relay", RELAY},
	{"release", RELEASE},
	{"release_all_locks", RELEASE_ALL_LOCKS},
	{"release_lock", RELEASE_LOCK},
	{"remove", REMOVE},
	{"rename", RENAME},
	{"reorganize", REORGANIZE},
	{"repair", REPAIR},
	{"repeat", UNUSED},
	{"repeatable", REPEATABLE},
	{"replace", REPLACE},
	{"require", UNUSED},
	{"resignal", UNUSED},
	{"respect", RESPECT},
	{"restrict", RESTRICT},
	{"return", UNUSED},
	{"returning", RETURNING},
	{"retry", RETRY},
	{"revert", REVERT},
	{"revoke", UNUSED},
	{"right", RIGHT},
	{"rlike", RLIKE},
	{"rollback", ROLLBACK},
	{"rollup", ROLLUP},
	{"row", ROW},
	{"row_format", ROW_FORMAT},
	{"row_number", ROW_NUMBER},
	{"rows", ROWS},
	{"rtrim", RTRIM},
	{"s3", S3},
	{"savepoint", SAVEPOINT},
	{"schema", SCHEMA},
	{"schemas", SCHEMAS},
	{"second", SECOND},
	{"second_microsecond", SECOND_MICROSECOND},
	{"secondary_engine_attribute", SECONDARY_ENGINE_ATTRIBUTE},
	{"security", SECURITY},
	{"select", SELECT},
	{"sensitive", UNUSED},
	{"separator", SEPARATOR},
	{"sequence", SEQUENCE},
	{"serializable", SERIALIZABLE},
	{"session", SESSION},
	{"set", SET},
	{"share", SHARE},
	{"shared", SHARED},
	{"show", SHOW},
	{"signal", UNUSED},
	{"signed", SIGNED},
	{"simple", SIMPLE},
	{"skip", SKIP},
	{"slow", SLOW},
	{"smallint", SMALLINT},
	{"snapshot", SNAPSHOT},
	{"spatial", SPATIAL},
	{"specific", UNUSED},
	{"sql", SQL},
	{"sqlexception", UNUSED},
	{"sqlstate", UNUSED},
	{"sqlwarning", UNUSED},
	{"sql_big_result", UNUSED},
	{"sql_cache", SQL_CACHE},
	{"sql_calc_found_rows", SQL_CALC_FOUND_ROWS},
	{"sql_no_cache", SQL_NO_CACHE},
	{"sql_small_result", UNUSED},
	{"sql_tsi_day", SQL_TSI_DAY},
	{"sql_tsi_week", SQL_TSI_WEEK},
	{"sql_tsi_hour", SQL_TSI_HOUR},
	{"sql_tsi_minute", SQL_TSI_MINUTE},
	{"sql_tsi_month", SQL_TSI_MONTH},
	{"sql_tsi_quarter", SQL_TSI_QUARTER},
	{"sql_tsi_second", SQL_TSI_SECOND},
	{"sql_tsi_microsecond", SQL_TSI_MICROSECOND},
	{"sql_tsi_year", SQL_TSI_YEAR},
	{"ssl", UNUSED},
	{"start", START},
	{"startpoint", ST_StartPoint},
	{"starting", STARTING},
	{"stats_auto_recalc", STATS_AUTO_RECALC},
	{"stats_persistent", STATS_PERSISTENT},
	{"stats_sample_pages", STATS_SAMPLE_PAGES},
	{"status", STATUS},
	{"std", STD},
	{"stddev", STDDEV},
	{"stddev_pop", STDDEV_POP},
	{"stddev_samp", STDDEV_SAMP},
	{"storage", STORAGE},
	{"stored", STORED},
	{"straight_join", STRAIGHT_JOIN},
	{"stream", STREAM},
	{"st_area", ST_Area},
	{"st_asbinary", ST_AsBinary},
	{"st_asgeojson", ST_AsGeoJSON},
	{"st_astext", ST_AsText},
	{"st_aswkb", ST_AsBinary},
	{"st_aswkt", ST_AsText},
	{"st_centroid", ST_Centroid},
	{"st_dimension", ST_Dimension},
	{"st_endpoint", ST_EndPoint},
	{"st_envelope", ST_Envelope},
	{"st_exteriorring", ST_ExteriorRing},
	{"st_geohash", ST_GeoHash},
	{"st_geomcollfromtext", ST_GeometryCollectionFromText},
	{"st_geomcollfromtxt", ST_GeometryCollectionFromText},
	{"st_geomcollfromwkb", ST_GeometryCollectionFromWKB},
	{"st_geometrycollectionfromtext", ST_GeometryCollectionFromText},
	{"st_geometrycollectionfromwkb", ST_GeometryCollectionFromWKB},
	{"st_geometryfromtext", ST_GeometryFromText},
	{"st_geometryfromwkb", ST_GeometryFromWKB},
	{"st_geometryn", ST_GeometryN},
	{"st_geometrytype", ST_GeometryType},
	{"st_geomfromgeojson", ST_GeomFromGeoJSON},
	{"st_geomfromtext", ST_GeometryFromText},
	{"st_geomfromwkb", ST_GeometryFromWKB},
	{"st_interiorringn", ST_InteriorRingN},
	{"st_isclosed", ST_IsClosed},
	{"st_isempty", ST_IsEmpty},
	{"st_issimple", ST_IsSimple},
	{"st_latfromgeohash", ST_LatFromGeoHash},
	{"st_latitude", ST_Latitude},
	{"st_length", ST_Length},
	{"st_linefromtext", ST_LineStringFromText},
	{"st_linefromwkb", ST_LineStringFromWKB},
	{"st_linestringfromtext", ST_LineStringFromText},
	{"st_linestringfromwkb", ST_LineStringFromWKB},
	{"st_longfromgeohash", ST_LongFromGeoHash},
	{"st_longitude", ST_Longitude},
	{"st_mlinefromtext", ST_MultiLineStringFromText},
	{"st_mlinefromwkb", ST_MultiLineStringFromWKB},
	{"st_mpointfromtext", ST_MultiPointFromText},
	{"st_mpointfromwkb", ST_MultiPointFromWKB},
	{"st_mpolyfromtext", ST_MultiPolygonFromText},
	{"st_mpolyfromwkb", ST_MultiPolygonFromWKB},
	{"st_multilinestringfromtext", ST_MultiLineStringFromText},
	{"st_multilinestringfromwkb", ST_MultiLineStringFromWKB},
	{"st_multipointfromtext", ST_MultiPointFromText},
	{"st_multipointfromwkb", ST_MultiPointFromWKB},
	{"st_multipolygonfromtext", ST_MultiPolygonFromText},
	{"st_multipolygonfromwkb", ST_MultiPolygonFromWKB},
	{"st_numgeometries", ST_NumGeometries},
	{"st_numpoints", ST_NumPoints},
	{"st_numinteriorring", ST_NumInteriorRings},
	{"st_numinteriorrings", ST_NumInteriorRings},
	{"st_pointfromgeohash", ST_PointFromGeoHash},
	{"st_pointfromtext", ST_PointFromText},
	{"st_pointfromwkb", ST_PointFromWKB},
	{"st_pointn", ST_PointN},
	{"st_polyfromtext", ST_PolygonFromText},
	{"st_polyfromwkb", ST_PolygonFromWKB},
	{"st_polygonfromtext", ST_PolygonFromText},
	{"st_polygonfromwkb", ST_PolygonFromWKB},
	{"st_startpoint", ST_StartPoint},
	{"st_x", ST_X},
	{"st_y", ST_Y},
	{"subdate", SUBDATE},
	{"sum", SUM},
	{"sysdate", SYSDATE},
	{"system", UNUSED},
	{"table", TABLE},
	{"tables", TABLES},
	{"tablespace", TABLESPACE},
	{"temporary", TEMPORARY},
	{"temptable", TEMPTABLE},
	{"terminated", TERMINATED},
	{"text", TEXT},
	{"than", THAN},
	{"then", THEN},
	{"throttle", THROTTLE},
	{"time", TIME},
	{"timestamp", TIMESTAMP},
	{"timestampadd", TIMESTAMPADD},
	{"timestampdiff", TIMESTAMPDIFF},
	{"tinyblob", TINYBLOB},
	{"tinyint", TINYINT},
	{"tinytext", TINYTEXT},
	{"to", TO},
	{"trailing", TRAILING},
	{"transaction", TRANSACTION},
	{"tree", TREE},
	{"traditional", TRADITIONAL},
	{"trigger", TRIGGER},
	{"triggers", TRIGGERS},
	{"true", TRUE},
	{"truncate", TRUNCATE},
	{"trim", TRIM},
	{"unbounded", UNBOUNDED},
	{"uncommitted", UNCOMMITTED},
	{"undefined", UNDEFINED},
	{"undo", UNUSED},
	{"unicode", UNICODE},
	{"union", UNION},
	{"unique", UNIQUE},
	{"unknown", UNKNOWN},
	{"unlock", UNLOCK},
	{"unsigned", UNSIGNED},
	{"unthrottle", UNTHROTTLE},
	{"update", UPDATE},
	{"updatexml", UpdateXML},
	{"upgrade", UPGRADE},
	{"usage", UNUSED},
	{"use", USE},
	{"user", USER},
	{"user_resources", USER_RESOURCES},
	{"using", USING},
	{"utc_date", UTC_DATE},
	{"utc_time", UTC_TIME},
	{"utc_timestamp", UTC_TIMESTAMP},
	{"validation", VALIDATION},
	{"values", VALUES},
	{"var_pop", VAR_POP},
	{"var_samp", VAR_SAMP},
	{"variables", VARIABLES},
	{"varbinary", VARBINARY},
	{"varchar", VARCHAR},
	{"varcharacter", UNUSED},
	{"variance", VARIANCE},
	{"varying", UNUSED},
	{"vexplain", VEXPLAIN},
	{"vgtid_executed", VGTID_EXECUTED},
	{"virtual", VIRTUAL},
	{"vindex", VINDEX},
	{"vindexes", VINDEXES},
	{"view", VIEW},
	{"vitess", VITESS},
	{"vitess_keyspaces", VITESS_KEYSPACES},
	{"vitess_metadata", VITESS_METADATA},
	{"vitess_migration", VITESS_MIGRATION},
	{"vitess_migrations", VITESS_MIGRATIONS},
	{"vitess_replication_status", VITESS_REPLICATION_STATUS},
	{"vitess_shards", VITESS_SHARDS},
	{"vitess_tablets", VITESS_TABLETS},
	{"vitess_target", VITESS_TARGET},
	{"vitess_throttled_apps", VITESS_THROTTLED_APPS},
	{"vitess_throttler", VITESS_THROTTLER},
	{"vschema", VSCHEMA},
	{"vstream", VSTREAM},
	{"vtexplain", VTEXPLAIN},
	{"warnings", WARNINGS},
	{"wait_for_executed_gtid_set", WAIT_FOR_EXECUTED_GTID_SET},
	{"wait_until_sql_thread_after_gtids", WAIT_UNTIL_SQL_THREAD_AFTER_GTIDS},
	{"week", WEEK},
	{"weight_string", WEIGHT_STRING},
	{"when", WHEN},
	{"where", WHERE},
	{"while", UNUSED},
	{"window", WINDOW},
	{"with", WITH},
	{"without", WITHOUT},
	{"work", WORK},
	{"write", WRITE},
	{"visible", VISIBLE},
	{"xor", XOR},
	{"year", YEAR},
	{"year_month", YEAR_MONTH},
	{"zerofill", ZEROFILL},
}

// keywordStrings contains the reverse mapping of token to keyword strings
var keywordStrings = map[int]string{}
var keywordVals = map[string]int{}

// keywordLookupTable is a perfect hash map that maps **case insensitive** keyword names to their ids
var keywordLookupTable *caseInsensitiveTable

type caseInsensitiveTable struct {
	h map[uint64]keyword
}

func buildCaseInsensitiveTable(keywords []keyword) *caseInsensitiveTable {
	table := &caseInsensitiveTable{
		h: make(map[uint64]keyword, len(keywords)),
	}

	for _, kw := range keywords {
		hash := fnv1aIstr(offset64, kw.name)
		if _, exists := table.h[hash]; exists {
			panic("collision in caseInsensitiveTable")
		}
		table.h[hash] = kw
	}
	return table
}

func (cit *caseInsensitiveTable) LookupString(name string) (int, bool) {
	hash := fnv1aIstr(offset64, name)
	if candidate, ok := cit.h[hash]; ok {
		return candidate.id, candidate.matchStr(name)
	}
	return 0, false
}

func init() {
	for _, kw := range keywords {
		if kw.id == UNUSED {
			continue
		}
		if kw.name != strings.ToLower(kw.name) {
			panic(fmt.Sprintf("keyword %q must be lowercase in table", kw.name))
		}
		keywordStrings[kw.id] = kw.name
		keywordVals[kw.name] = kw.id
	}

	keywordLookupTable = buildCaseInsensitiveTable(keywords)
}

// KeywordString returns the string corresponding to the given keyword
func KeywordString(id int) string {
	str, ok := keywordStrings[id]
	if !ok {
		return ""
	}
	return str
}

const offset64 = uint64(14695981039346656037)
const prime64 = uint64(1099511628211)

func fnv1aIstr(h uint64, s string) uint64 {
	for i := 0; i < len(s); i++ {
		c := s[i]
		if 'A' <= c && c <= 'Z' {
			c += 'a' - 'A'
		}
		h = (h ^ uint64(c)) * prime64
	}
	return h
}