Package org.jgroups.protocols
Class PDC
- java.lang.Object
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- org.jgroups.stack.Protocol
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- org.jgroups.protocols.PDC
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public class PDC extends Protocol
Persistent Discovery Cache. Caches mapping between logical and physical addresses on disk, merges them with the results of the get physical address(es) events. This is done by intercepting the get and set physical address(es) event. Needs to be placed between the transport and the discovery protocol. The disk cache stores each mapping in a separate file, named by the logical address.- Since:
- 3.3
- Author:
- Bela Ban
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static class
PDC.Mapping
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Field Summary
Fields Modifier and Type Field Description protected java.util.concurrent.ConcurrentMap<Address,PhysicalAddress>
cache
protected java.lang.String
cache_dir
protected java.io.FilenameFilter
filter
protected Address
local_addr
protected java.io.File
root_dir
protected static java.lang.String
SUFFIX
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Fields inherited from class org.jgroups.stack.Protocol
after_creation_hook, down_prot, ergonomics, id, log, stack, stats, up_prot
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Constructor Summary
Constructors Constructor Description PDC()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description protected static java.lang.String
addressAsString(Address address)
protected void
createDiskCacheFile()
protected boolean
deleteFile(java.io.File file)
Attempts to delete the provided file.
Logging is performed on the resultjava.lang.Object
down(Event evt)
An event is to be sent down the stack.void
init()
Called after instance has been created (null constructor) and before protocol is started.java.lang.String
printCache()
protected void
readCacheFromDisk()
Reads all mappings from diskprotected void
removeNodeFromDisk(Address logical_addr)
protected void
writeNodeToDisk(Address logical_addr, PhysicalAddress physical_addr)
protected java.io.File
writeToTempFile(java.io.File dir, Address logical_addr, Address physical_addr, java.lang.String logical_name)
Writes the data to a temporary file.
The file is stored in the same directory as the other cluster files but is given the .tmp suffix-
Methods inherited from class org.jgroups.stack.Protocol
accept, afterCreationHook, destroy, down, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, resetStats, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, start, statsEnabled, stop, up, up, up
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Field Detail
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cache
protected final java.util.concurrent.ConcurrentMap<Address,PhysicalAddress> cache
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cache_dir
protected java.lang.String cache_dir
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SUFFIX
protected static final java.lang.String SUFFIX
- See Also:
- Constant Field Values
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root_dir
protected java.io.File root_dir
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filter
protected java.io.FilenameFilter filter
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local_addr
protected Address local_addr
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Method Detail
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printCache
public java.lang.String printCache()
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init
public void init() throws java.lang.Exception
Description copied from class:Protocol
Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.
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down
public java.lang.Object down(Event evt)
Description copied from class:Protocol
An event is to be sent down the stack. A protocol may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the protocol may need to add a header to it (or do nothing at all) before sending it down the stack usingdown_prot.down()
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createDiskCacheFile
protected void createDiskCacheFile() throws java.io.IOException
- Throws:
java.io.IOException
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readCacheFromDisk
protected void readCacheFromDisk()
Reads all mappings from disk
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writeNodeToDisk
protected void writeNodeToDisk(Address logical_addr, PhysicalAddress physical_addr)
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writeToTempFile
protected java.io.File writeToTempFile(java.io.File dir, Address logical_addr, Address physical_addr, java.lang.String logical_name) throws java.lang.Exception
Writes the data to a temporary file.
The file is stored in the same directory as the other cluster files but is given the .tmp suffix- Parameters:
dir
- The disk cache root dirlogical_addr
- The logical addressphysical_addr
- The physical address- Returns:
- Throws:
java.lang.Exception
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removeNodeFromDisk
protected void removeNodeFromDisk(Address logical_addr)
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addressAsString
protected static java.lang.String addressAsString(Address address)
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deleteFile
protected boolean deleteFile(java.io.File file)
Attempts to delete the provided file.
Logging is performed on the result- Parameters:
file
-- Returns:
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