Files
chaisql/internal/sql/parser/create.go
2021-07-02 18:41:33 +04:00

588 lines
14 KiB
Go

package parser
import (
"math"
"github.com/genjidb/genji/internal/database"
"github.com/genjidb/genji/internal/expr"
"github.com/genjidb/genji/internal/query/statement"
"github.com/genjidb/genji/internal/sql/scanner"
"github.com/genjidb/genji/internal/stringutil"
)
// parseCreateStatement parses a create string and returns a Statement AST object.
// This function assumes the CREATE token has already been consumed.
func (p *Parser) parseCreateStatement() (statement.Statement, error) {
tok, pos, lit := p.ScanIgnoreWhitespace()
switch tok {
case scanner.TABLE:
return p.parseCreateTableStatement()
case scanner.UNIQUE:
if tok, pos, lit := p.ScanIgnoreWhitespace(); tok != scanner.INDEX {
return nil, newParseError(scanner.Tokstr(tok, lit), []string{"INDEX"}, pos)
}
return p.parseCreateIndexStatement(true)
case scanner.INDEX:
return p.parseCreateIndexStatement(false)
case scanner.SEQUENCE:
return p.parseCreateSequenceStatement()
}
return nil, newParseError(scanner.Tokstr(tok, lit), []string{"TABLE", "INDEX", "SEQUENCE"}, pos)
}
// parseCreateTableStatement parses a create table string and returns a Statement AST object.
// This function assumes the CREATE TABLE tokens have already been consumed.
func (p *Parser) parseCreateTableStatement() (*statement.CreateTableStmt, error) {
var stmt statement.CreateTableStmt
var err error
// Parse IF NOT EXISTS
stmt.IfNotExists, err = p.parseOptional(scanner.IF, scanner.NOT, scanner.EXISTS)
if err != nil {
return nil, err
}
// Parse table name
stmt.Info.TableName, err = p.parseIdent()
if err != nil {
return nil, err
}
// parse field constraints
err = p.parseConstraints(&stmt)
return &stmt, err
}
func (p *Parser) parseFieldDefinition(fc *database.FieldConstraint) (err error) {
fc.Path, err = p.parsePath()
if err != nil {
return err
}
fc.Type, err = p.parseType()
if err != nil {
p.Unscan()
}
err = p.parseFieldConstraint(fc)
if err != nil {
return err
}
if fc.Type.IsAny() && fc.DefaultValue == nil && !fc.IsNotNull && !fc.IsPrimaryKey && !fc.IsUnique {
tok, pos, lit := p.ScanIgnoreWhitespace()
return newParseError(scanner.Tokstr(tok, lit), []string{"CONSTRAINT", "TYPE"}, pos)
}
return nil
}
func (p *Parser) parseConstraints(stmt *statement.CreateTableStmt) error {
// Parse ( token.
if ok, err := p.parseOptional(scanner.LPAREN); !ok || err != nil {
return err
}
// if set to true, the parser must no longer
// expect field definitions, but only table constraints.
var parsingTableConstraints bool
// Parse constraints.
for {
// we start by checking if it is a table constraint,
// as it's easier to determine
ok, err := p.parseTableConstraint(stmt)
if err != nil {
return err
}
// no table constraint found
if !ok && parsingTableConstraints {
tok, pos, lit := p.ScanIgnoreWhitespace()
return newParseError(scanner.Tokstr(tok, lit), []string{"CONSTRAINT", ")"}, pos)
}
// only PRIMARY KEY(path) is currently supported.
if ok {
parsingTableConstraints = true
}
// if set to false, we are still parsing field definitions
if !parsingTableConstraints {
var fc database.FieldConstraint
err = p.parseFieldDefinition(&fc)
if err != nil {
return err
}
err = stmt.Info.FieldConstraints.Add(&fc)
if err != nil {
return err
}
}
if tok, _, _ := p.ScanIgnoreWhitespace(); tok != scanner.COMMA {
p.Unscan()
break
}
}
// Parse required ) token.
if err := p.parseTokens(scanner.RPAREN); err != nil {
return err
}
// ensure only one primary key
var pkFound bool
for _, fc := range stmt.Info.FieldConstraints {
if fc.IsPrimaryKey {
if pkFound {
return stringutil.Errorf("table %q has more than one primary key", stmt.Info.TableName)
}
pkFound = true
}
}
return nil
}
func (p *Parser) parseFieldConstraint(fc *database.FieldConstraint) error {
for {
tok, pos, lit := p.ScanIgnoreWhitespace()
switch tok {
case scanner.PRIMARY:
// Parse "KEY"
if err := p.parseTokens(scanner.KEY); err != nil {
return err
}
// if it's already a primary key we return an error
if fc.IsPrimaryKey {
return newParseError(scanner.Tokstr(tok, lit), []string{"CONSTRAINT", ")"}, pos)
}
fc.IsPrimaryKey = true
case scanner.NOT:
// Parse "NULL"
if err := p.parseTokens(scanner.NULL); err != nil {
return err
}
// if it's already not null we return an error
if fc.IsNotNull {
return newParseError(scanner.Tokstr(tok, lit), []string{"CONSTRAINT", ")"}, pos)
}
fc.IsNotNull = true
case scanner.DEFAULT:
// if it has already a default value we return an error
if fc.HasDefaultValue() {
return newParseError(scanner.Tokstr(tok, lit), []string{"CONSTRAINT", ")"}, pos)
}
// Parse default value expression.
// Only a few tokens are allowed.
e, err := p.parseExprWithMinPrecedence(scanner.EQ.Precedence(),
scanner.EQ,
scanner.NEQ,
scanner.BITWISEOR,
scanner.BITWISEXOR,
scanner.BITWISEAND,
scanner.LT,
scanner.LTE,
scanner.GT,
scanner.GTE,
scanner.ADD,
scanner.SUB,
scanner.MUL,
scanner.DIV,
scanner.MOD,
scanner.CONCAT,
scanner.INTEGER,
scanner.NUMBER,
scanner.STRING,
scanner.TRUE,
scanner.FALSE,
scanner.NULL,
scanner.LPAREN, // only opening parenthesis are necessary
scanner.LBRACKET, // only opening brackets are necessary
scanner.NEXT,
)
if err != nil {
return err
}
fc.DefaultValue = expr.Constraint(e)
case scanner.UNIQUE:
// if it's already unique we return an error
if fc.IsUnique {
return newParseError(scanner.Tokstr(tok, lit), []string{"CONSTRAINT", ")"}, pos)
}
fc.IsUnique = true
default:
p.Unscan()
return nil
}
}
}
func (p *Parser) parseTableConstraint(stmt *statement.CreateTableStmt) (bool, error) {
var err error
tok, _, _ := p.ScanIgnoreWhitespace()
switch tok {
case scanner.PRIMARY:
// Parse "KEY ("
err = p.parseTokens(scanner.KEY, scanner.LPAREN)
if err != nil {
return false, err
}
primaryKeyPath, err := p.parsePath()
if err != nil {
return false, err
}
// Parse ")"
err = p.parseTokens(scanner.RPAREN)
if err != nil {
return false, err
}
if pk := stmt.Info.FieldConstraints.GetPrimaryKey(); pk != nil {
return false, stringutil.Errorf("table %q has more than one primary key", stmt.Info.TableName)
}
fc := stmt.Info.FieldConstraints.Get(primaryKeyPath)
if fc == nil {
err = stmt.Info.FieldConstraints.Add(&database.FieldConstraint{
Path: primaryKeyPath,
IsPrimaryKey: true,
})
if err != nil {
return false, err
}
} else {
fc.IsPrimaryKey = true
}
return true, nil
case scanner.UNIQUE:
// Parse "("
err = p.parseTokens(scanner.LPAREN)
if err != nil {
return false, err
}
uniquePath, err := p.parsePath()
if err != nil {
return false, err
}
// Parse ")"
err = p.parseTokens(scanner.RPAREN)
if err != nil {
return false, err
}
fc := stmt.Info.FieldConstraints.Get(uniquePath)
if fc == nil {
err = stmt.Info.FieldConstraints.Add(&database.FieldConstraint{
Path: uniquePath,
IsUnique: true,
})
if err != nil {
return false, err
}
} else {
fc.IsUnique = true
}
return true, nil
default:
p.Unscan()
return false, nil
}
}
// parseCreateIndexStatement parses a create index string and returns a Statement AST object.
// This function assumes the CREATE INDEX or CREATE UNIQUE INDEX tokens have already been consumed.
func (p *Parser) parseCreateIndexStatement(unique bool) (*statement.CreateIndexStmt, error) {
var err error
var stmt statement.CreateIndexStmt
stmt.Info.Unique = unique
// Parse IF NOT EXISTS
stmt.IfNotExists, err = p.parseOptional(scanner.IF, scanner.NOT, scanner.EXISTS)
if err != nil {
return nil, err
}
// Parse optional index name
stmt.Info.IndexName, err = p.parseIdent()
if err != nil {
// if IF NOT EXISTS is set, index name is mandatory
if stmt.IfNotExists {
return nil, err
}
p.Unscan()
}
// Parse "ON"
if err := p.parseTokens(scanner.ON); err != nil {
return nil, err
}
// Parse table name
stmt.Info.TableName, err = p.parseIdent()
if err != nil {
return nil, err
}
paths, err := p.parsePathList()
if err != nil {
return nil, err
}
if len(paths) == 0 {
tok, pos, lit := p.ScanIgnoreWhitespace()
return nil, newParseError(scanner.Tokstr(tok, lit), []string{"("}, pos)
}
stmt.Info.Paths = paths
return &stmt, nil
}
// This function assumes the CREATE SEQUENCE tokens have already been consumed.
func (p *Parser) parseCreateSequenceStatement() (*statement.CreateSequenceStmt, error) {
var stmt statement.CreateSequenceStmt
var err error
// Parse IF NOT EXISTS
stmt.IfNotExists, err = p.parseOptional(scanner.IF, scanner.NOT, scanner.EXISTS)
if err != nil {
return nil, err
}
// Parse sequence name
stmt.Info.Name, err = p.parseIdent()
if err != nil {
return nil, err
}
var hasAsInt, hasNoMin, hasNoMax, hasNoCycle bool
var min, max, incrementBy, start, cache *int64
for {
// Parse AS [any int type]
// Only integers are supported
if ok, _ := p.parseOptional(scanner.AS); ok {
tok, pos, lit := p.ScanIgnoreWhitespace()
switch tok {
case scanner.TYPEINTEGER, scanner.TYPEINT, scanner.TYPEINT2, scanner.TYPEINT8, scanner.TYPETINYINT,
scanner.TYPEBIGINT, scanner.TYPEMEDIUMINT, scanner.TYPESMALLINT:
default:
return nil, newParseError(scanner.Tokstr(tok, lit), []string{"INT"}, pos)
}
if hasAsInt {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
hasAsInt = true
continue
}
// Parse INCREMENT [BY] integer
if ok, _ := p.parseOptional(scanner.INCREMENT); ok {
// parse optional BY token
_, _ = p.parseOptional(scanner.BY)
if incrementBy != nil {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
i, err := p.parseInteger()
if err != nil {
return nil, err
}
if i == 0 {
return nil, &ParseError{Message: "INCREMENT must not be zero"}
}
incrementBy = &i
continue
}
// Parse NO [MINVALUE | MAXVALUE | CYCLE]
if ok, _ := p.parseOptional(scanner.NO); ok {
tok, pos, lit := p.ScanIgnoreWhitespace()
if tok == scanner.MINVALUE {
if hasNoMin {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
hasNoMin = true
continue
}
if tok == scanner.MAXVALUE {
if hasNoMax {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
hasNoMax = true
continue
}
if tok == scanner.CYCLE {
if hasNoCycle {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
hasNoCycle = true
continue
}
return nil, newParseError(scanner.Tokstr(tok, lit), []string{"MINVALUE", "MAXVALUE", "CYCLE"}, pos)
}
// Parse MINVALUE integer
if ok, _ := p.parseOptional(scanner.MINVALUE); ok {
if hasNoMin || min != nil {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
i, err := p.parseInteger()
if err != nil {
return nil, err
}
min = &i
continue
}
// Parse MAXVALUE integer
if ok, _ := p.parseOptional(scanner.MAXVALUE); ok {
if hasNoMax || max != nil {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
i, err := p.parseInteger()
if err != nil {
return nil, err
}
max = &i
continue
}
// Parse START [WITH] integer
if ok, _ := p.parseOptional(scanner.START); ok {
// parse optional WITH token
_, _ = p.parseOptional(scanner.WITH)
if start != nil {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
i, err := p.parseInteger()
if err != nil {
return nil, err
}
start = &i
continue
}
// Parse CACHE integer
if ok, _ := p.parseOptional(scanner.CACHE); ok {
if cache != nil {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
v, err := p.parseInteger()
if err != nil {
return nil, err
}
if v < 0 {
return nil, &ParseError{Message: "cache value must be positive"}
}
cache = &v
continue
}
// Parse CYCLE
if ok, _ := p.parseOptional(scanner.CYCLE); ok {
if hasNoCycle || stmt.Info.Cycle {
return nil, &ParseError{Message: "conflicting or redundant options"}
}
stmt.Info.Cycle = true
continue
}
break
}
// default value for increment is 1
if incrementBy != nil {
stmt.Info.IncrementBy = *incrementBy
} else {
stmt.Info.IncrementBy = 1
}
// determine if the sequence is ascending or descending
asc := stmt.Info.IncrementBy > 0
// default value for min is 1 if ascending
// or the minimum value of ints if descending
if min != nil {
stmt.Info.Min = *min
} else if asc {
stmt.Info.Min = 1
} else {
stmt.Info.Min = math.MinInt64
}
// default value for max is the maximum value of ints if ascending
// or the -1 if descending
if max != nil {
stmt.Info.Max = *max
} else if asc {
stmt.Info.Max = math.MaxInt64
} else {
stmt.Info.Max = -1
}
// check if min > max
if stmt.Info.Min > stmt.Info.Max {
return nil, &ParseError{Message: stringutil.Sprintf("MINVALUE (%d) must be less than MAXVALUE (%d)", stmt.Info.Min, stmt.Info.Max)}
}
// default value for start is min if ascending
// or max if descending
if start != nil {
stmt.Info.Start = *start
} else if asc {
stmt.Info.Start = stmt.Info.Min
} else {
stmt.Info.Start = stmt.Info.Max
}
// check if min < start < max
if stmt.Info.Start < stmt.Info.Min {
return nil, &ParseError{Message: stringutil.Sprintf("START value (%d) cannot be less than MINVALUE (%d)", stmt.Info.Start, stmt.Info.Min)}
}
if stmt.Info.Start > stmt.Info.Max {
return nil, &ParseError{Message: stringutil.Sprintf("START value (%d) cannot be greater than MAXVALUE (%d)", stmt.Info.Start, stmt.Info.Max)}
}
// default for cache is 1
if cache != nil {
stmt.Info.Cache = uint64(*cache)
} else {
stmt.Info.Cache = 1
}
return &stmt, err
}