com.facebook.buck.rules.keys.hasher

Interface RuleKeyHasher<HASH>

All Known Implementing Classes:

CountingRuleKeyHasher, ForwardingRuleKeyHasher, GuavaRuleKeyHasher, StringRuleKeyHasher, ThriftRuleKeyHasher

public interface RuleKeyHasher<HASH>

A hasher used for the rule key construction.

Warning: The result of calling any methods after calling hash() is undefined.

Chunks of data that are put into the RuleKeyHasher are delimited. Delimiting details are implementation dependent, but one common way is to hash the size of the data along with the data itself, for each operation performed. For example, the following three expressions should ideally all generate different hash codes:

 newHasher().putByte(b1).putByte(b2).putByte(b3).hash()
 newHasher().putByte(b1).putBytes(new byte[] { b2, b3 }).hash()
 newHasher().putBytes(new byte[] { b1, b2, b3 }).hash()
 

Note, Buck hashes both field values and field names (keys) when constructing rule keys. E.g.:

{@code
 public class myRule implements BuildRule {

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	RuleKeyHasher.Container
static class	RuleKeyHasher.Wrapper

Method Summary

Modifier and Type	Method and Description
HASH	hash() Computes the final hash.
RuleKeyHasher<HASH>	putArchiveMemberPath(Path relativeArchivePath, Path archiveMemberPath, com.google.common.hash.HashCode hash)
RuleKeyHasher<HASH>	putBoolean(boolean val)
RuleKeyHasher<HASH>	putBuildTarget(BuildTarget buildTarget)
RuleKeyHasher<HASH>	putBuildTargetSourcePath(BuildTargetSourcePath buildTargetSourcePath)
RuleKeyHasher<HASH>	putBytes(byte[] bytes)
RuleKeyHasher<HASH>	putCharacter(char val)
RuleKeyHasher<HASH>	putContainer(RuleKeyHasher.Container container, int length) Puts the container signature
RuleKeyHasher<HASH>	putKey(String key) Puts the field's key (i.e.
RuleKeyHasher<HASH>	putKeyPath(Path key) Puts the stringified path as a key.
RuleKeyHasher<HASH>	putNonHashingPath(Path path)
RuleKeyHasher<HASH>	putNull() Puts the field's value, Java types
RuleKeyHasher<HASH>	putNumber(Number val)
RuleKeyHasher<HASH>	putPath(Path path, com.google.common.hash.HashCode hash)
RuleKeyHasher<HASH>	putPattern(Pattern pattern)
RuleKeyHasher<HASH>	putRuleKey(RuleKey ruleKey)
RuleKeyHasher<HASH>	putRuleType(RuleType ruleType)
RuleKeyHasher<HASH>	putSha1(Sha1HashCode sha1) Puts the field's value, Buck specific types
RuleKeyHasher<HASH>	putString(String val)
RuleKeyHasher<HASH>	putWrapper(RuleKeyHasher.Wrapper wrapper)

Method Detail

putKey

RuleKeyHasher<HASH> putKey(String key)

Puts the field's key (i.e. the name of the field)

putKeyPath

RuleKeyHasher<HASH> putKeyPath(Path key)

Puts the stringified path as a key.

putNull

RuleKeyHasher<HASH> putNull()

Puts the field's value, Java types

putCharacter

RuleKeyHasher<HASH> putCharacter(char val)

putBoolean

RuleKeyHasher<HASH> putBoolean(boolean val)

putNumber

RuleKeyHasher<HASH> putNumber(Number val)

putString

RuleKeyHasher<HASH> putString(String val)

putBytes

RuleKeyHasher<HASH> putBytes(byte[] bytes)

putPattern

RuleKeyHasher<HASH> putPattern(Pattern pattern)

putSha1

RuleKeyHasher<HASH> putSha1(Sha1HashCode sha1)

Puts the field's value, Buck specific types

putPath

RuleKeyHasher<HASH> putPath(Path path,
                            com.google.common.hash.HashCode hash)

putArchiveMemberPath

RuleKeyHasher<HASH> putArchiveMemberPath(Path relativeArchivePath,
                                         Path archiveMemberPath,
                                         com.google.common.hash.HashCode hash)

Parameters:

relativeArchivePath - relative path to archive.

archiveMemberPath - path to archive member.

putNonHashingPath

RuleKeyHasher<HASH> putNonHashingPath(Path path)

putRuleKey

RuleKeyHasher<HASH> putRuleKey(RuleKey ruleKey)

putRuleType

RuleKeyHasher<HASH> putRuleType(RuleType ruleType)

putBuildTarget

RuleKeyHasher<HASH> putBuildTarget(BuildTarget buildTarget)

putBuildTargetSourcePath

RuleKeyHasher<HASH> putBuildTargetSourcePath(BuildTargetSourcePath buildTargetSourcePath)

putContainer

RuleKeyHasher<HASH> putContainer(RuleKeyHasher.Container container,
                                 int length)

Puts the container signature

putWrapper

RuleKeyHasher<HASH> putWrapper(RuleKeyHasher.Wrapper wrapper)

hash

HASH hash()

Computes the final hash.