Package graphql.parser

Class SafeTokenSource

java.lang.Object

graphql.parser.SafeTokenSource

All Implemented Interfaces:

org.antlr.v4.runtime.TokenSource

public class SafeTokenSource
extends java.lang.Object
implements org.antlr.v4.runtime.TokenSource

This token source can wrap a lexer and if it asks for more than a maximum number of tokens the user can take some action, typically throw an exception to stop lexing. It tracks the maximum number per token channel, so we have 3 at the moment, and they will all be tracked. This is used to protect us from evil input. The lexer will eagerly try to find all tokens at times and certain inputs (directives butted together for example) will cause the lexer to keep doing work even though before the tokens are presented back to the parser and hence before it has a chance to stop work once too much as been done.

Field Summary

Fields

Modifier and Type	Field	Description
private int[]	channelCounts
private org.antlr.v4.runtime.TokenSource	lexer
private int	maxTokens
private int	maxWhitespaceTokens
private java.util.function.BiConsumer<java.lang.Integer,org.antlr.v4.runtime.Token>	whenMaxTokensExceeded

Constructor Summary

Constructors

Constructor	Description
SafeTokenSource(org.antlr.v4.runtime.TokenSource lexer, int maxTokens, int maxWhitespaceTokens, java.util.function.BiConsumer<java.lang.Integer,org.antlr.v4.runtime.Token> whenMaxTokensExceeded)

Method Summary

Modifier and Type	Method	Description
private void	callbackIfMaxExceeded(int maxCount, int currentCount, org.antlr.v4.runtime.Token token)
int	getCharPositionInLine()
org.antlr.v4.runtime.CharStream	getInputStream()
int	getLine()
java.lang.String	getSourceName()
org.antlr.v4.runtime.TokenFactory<?>	getTokenFactory()
org.antlr.v4.runtime.Token	nextToken()
void	setTokenFactory(org.antlr.v4.runtime.TokenFactory<?> factory)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

lexer

private final org.antlr.v4.runtime.TokenSource lexer

maxTokens

private final int maxTokens

maxWhitespaceTokens

private final int maxWhitespaceTokens

whenMaxTokensExceeded

private final java.util.function.BiConsumer<java.lang.Integer,org.antlr.v4.runtime.Token> whenMaxTokensExceeded

channelCounts

private final int[] channelCounts

Constructor Detail

SafeTokenSource

public SafeTokenSource(org.antlr.v4.runtime.TokenSource lexer,
                       int maxTokens,
                       int maxWhitespaceTokens,
                       java.util.function.BiConsumer<java.lang.Integer,org.antlr.v4.runtime.Token> whenMaxTokensExceeded)

Method Detail

nextToken

public org.antlr.v4.runtime.Token nextToken()

Specified by:

nextToken in interface org.antlr.v4.runtime.TokenSource

callbackIfMaxExceeded

private void callbackIfMaxExceeded(int maxCount,
                                   int currentCount,
                                   org.antlr.v4.runtime.Token token)

getLine

public int getLine()

Specified by:

getLine in interface org.antlr.v4.runtime.TokenSource

getCharPositionInLine

public int getCharPositionInLine()

Specified by:

getCharPositionInLine in interface org.antlr.v4.runtime.TokenSource

getInputStream

public org.antlr.v4.runtime.CharStream getInputStream()

Specified by:

getInputStream in interface org.antlr.v4.runtime.TokenSource

getSourceName

public java.lang.String getSourceName()

Specified by:

getSourceName in interface org.antlr.v4.runtime.TokenSource

setTokenFactory

public void setTokenFactory(org.antlr.v4.runtime.TokenFactory<?> factory)

Specified by:

setTokenFactory in interface org.antlr.v4.runtime.TokenSource

getTokenFactory

public org.antlr.v4.runtime.TokenFactory<?> getTokenFactory()

Specified by:

getTokenFactory in interface org.antlr.v4.runtime.TokenSource