ClientSideIteratorScanner.ScannerTranslator (accumulo 1.4.5 API)

java.lang.Object
+
- org.apache.accumulo.core.client.ClientSideIteratorScanner.ScannerTranslator
+

+
+
All Implemented Interfaces:
+
org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
+
+
+
Enclosing class:
+
ClientSideIteratorScanner
+
+
+
+
```
public class ClientSideIteratorScanner.ScannerTranslator
+extends Object
+implements org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
```
+
A class that wraps a Scanner in a SortedKeyValueIterator so that other accumulo iterators can use it as a source.
+

+ +

+ + +
Field Summary
+ + + + + + + + + + +
Fields
Modifier and Type Field and Description
protected Scanner scanner
+

Fields
Modifier and Type	Field and Description
`protected Scanner`	`scanner`

+ +

+ + +
Constructor Summary
+ + + + + + + + +
Constructors
Constructor and Description
ClientSideIteratorScanner.ScannerTranslator(Scanner scanner) +
Constructs an accumulo iterator from a scanner.
+
+

Constructors
Constructor and Description
`ClientSideIteratorScanner.ScannerTranslator(Scanner scanner)` + Constructs an accumulo iterator from a scanner. +

+ +

+ + +

Method Summary

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Methods
Modifier and Type	Method and Description
`org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>`	`deepCopy(org.apache.accumulo.core.iterators.IteratorEnvironment env)` + Creates a deep copy of this iterator as though seek had not yet been called. +
`Key`	`getTopKey()` + Returns top key. +
`Value`	`getTopValue()` + Returns top value. +
`boolean`	`hasTop()` + Returns true if the iterator has more elements. +
`void`	`init(org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value> source, + Map<String,String> options, + org.apache.accumulo.core.iterators.IteratorEnvironment env)` + Initializes the iterator. +
`void`	`next()` + Advances to the next K,V pair. +
`void`	`seek(Range range, + Collection<ByteSequence> columnFamilies, + boolean inclusive)` + Seeks to the first key in the Range, restricting the resulting K,V pairs to those with the specified columns. +

+ + +
Methods inherited from class java.lang.Object
+clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

+ +
- + + +
  Field Detail
  + + + +
  - +
    scanner
    +
```
protected Scanner scanner
```
    +
  +
+ +
- + + +
  Constructor Detail
  + + + +
  - +
    ClientSideIteratorScanner.ScannerTranslator
    +
```
public ClientSideIteratorScanner.ScannerTranslator(Scanner scanner)
```
    +
    Constructs an accumulo iterator from a scanner.
    +
    Parameters:
    scanner - the scanner to iterate over
    +
  +
+ +
- + + +
  Method Detail
  + + + +
  - +
    init
    +
```
public void init(org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value> source,
+        Map<String,String> options,
+        org.apache.accumulo.core.iterators.IteratorEnvironment env)
+          throws IOException
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Initializes the iterator. Data should not be read from the source in this method.
    +
    +
    Specified by:
    +
    init in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Parameters:
    source - SortedKeyValueIterator source to read data from.
    options - Map map of string option names to option values.
    env - IteratorEnvironment environment in which iterator is being run.
    +
    Throws:
    +
    IOException - unused.
    +
  + + + +
  - +
    hasTop
    +
```
public boolean hasTop()
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Returns true if the iterator has more elements.
    +
    +
    Specified by:
    +
    hasTop in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Returns:
    true if the iterator has more elements.
    +
  + + + +
  - +
    next
    +
```
public void next()
+          throws IOException
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Advances to the next K,V pair. Note that in minor compaction scope and in non-full major compaction scopes the iterator may see deletion entries. These + entries should be preserved by all iterators except ones that are strictly scan-time iterators that will never be configured for the minc or majc scopes. + Deletion entries are only removed during full major compactions.
    +
    +
    Specified by:
    +
    next in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Throws:
    +
    IOException - if an I/O error occurs.
    +
  + + + +
  - +
    seek
    +
```
public void seek(Range range,
+        Collection<ByteSequence> columnFamilies,
+        boolean inclusive)
+          throws IOException
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Seeks to the first key in the Range, restricting the resulting K,V pairs to those with the specified columns. An iterator does not have to stop at the end + of the range. The whole range is provided so that iterators can make optimizations. + + Seek may be called multiple times with different parameters after SortedKeyValueIterator.init(org.apache.accumulo.core.iterators.SortedKeyValueIterator<K, V>, java.util.Map<java.lang.String, java.lang.String>, org.apache.accumulo.core.iterators.IteratorEnvironment) is called. + + Iterators that examine groups of adjacent key/value pairs (e.g. rows) to determine their top key and value should be sure that they properly handle a seek + to a key in the middle of such a group (e.g. the middle of a row). Even if the client always seeks to a range containing an entire group (a,c), the tablet + server could send back a batch of entries corresponding to (a,b], then reseek the iterator to range (b,c) when the scan is continued. + + columnFamilies is used, at the lowest level, to determine which data blocks inside of an RFile need to be opened for this iterator. This set of data + blocks is also the set of locality groups defined for the given table. If no columnFamilies are provided, the data blocks for all locality groups inside of + the correct RFile will be opened and seeked in an attempt to find the correct start key, regardless of the startKey in the range. + + In an Accumulo instance in which multiple locality groups exist for a table, it is important to ensure that columnFamilies is properly set to the + minimum required column families to ensure that data from separate locality groups is not inadvertently read.
    +
    +
    Specified by:
    +
    seek in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Parameters:
    range - Range of keys to iterate over.
    columnFamilies - Collection of column families to include or exclude.
    inclusive - boolean that indicates whether to include (true) or exclude (false) column families.
    +
    Throws:
    +
    IOException - if an I/O error occurs.
    +
  + + + +
  - +
    getTopKey
    +
```
public Key getTopKey()
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Returns top key. Can be called 0 or more times without affecting behavior of next() or hasTop(). Note that in minor compaction scope and in non-full major + compaction scopes the iterator may see deletion entries. These entries should be preserved by all iterators except ones that are strictly scan-time + iterators that will never be configured for the minc or majc scopes. Deletion entries are only removed during full major compactions.
    +
    +
    Specified by:
    +
    getTopKey in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Returns:
    K
    +
  + + + +
  - +
    getTopValue
    +
```
public Value getTopValue()
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Returns top value. Can be called 0 or more times without affecting behavior of next() or hasTop().
    +
    +
    Specified by:
    +
    getTopValue in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Returns:
    V
    +
  + + + +
  - +
    deepCopy
    +
```
public org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value> deepCopy(org.apache.accumulo.core.iterators.IteratorEnvironment env)
```
    +
    Description copied from interface: org.apache.accumulo.core.iterators.SortedKeyValueIterator
    +
    Creates a deep copy of this iterator as though seek had not yet been called. init should be called on an iterator before deepCopy is called. init should + not need to be called on the copy that is returned by deepCopy; that is, when necessary init should be called in the deepCopy method on the iterator it + returns. The behavior is unspecified if init is called after deepCopy either on the original or the copy.
    +
    +
    Specified by:
    +
    deepCopy in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<Key,Value>
    +
    Parameters:
    env - IteratorEnvironment environment in which iterator is being run.
    +
    Returns:
    SortedKeyValueIterator a copy of this iterator (with the same source and settings).
    +
  +
+

java.lang.Object
+
- org.apache.accumulo.core.client.impl.ScannerOptions
- +
  - org.apache.accumulo.core.client.ClientSideIteratorScanner
  +
+

+
+
All Implemented Interfaces:
+
Iterable<Map.Entry<Key,Value>>, Scanner, ScannerBase
+
+
+
+
```
public class ClientSideIteratorScanner
+extends org.apache.accumulo.core.client.impl.ScannerOptions
+implements Scanner
```
+
A scanner that instantiates iterators on the client side instead of on the tablet server. This can be useful for testing iterators or in cases where you + don't want iterators affecting the performance of tablet servers.
+
+ Suggested usage:
+ Scanner scanner = new ClientSideIteratorScanner(connector.createScanner(tableName, authorizations));
+
+ Iterators added to this scanner will be run in the client JVM. Separate scan iterators can be run on the server side and client side by adding iterators to + the source scanner (which will execute server side) and to the client side scanner (which will execute client side).
+

+ +

+ + +

Nested Class Summary

+ + + + + + + + + + +

Nested Classes
Modifier and Type	Class and Description
`class`	`ClientSideIteratorScanner.ScannerTranslator` + A class that wraps a Scanner in a SortedKeyValueIterator so that other accumulo iterators can use it as a source. +

+ +

+ + +
Field Summary
+
- + + +
  Fields inherited from class org.apache.accumulo.core.client.impl.ScannerOptions
  +fetchedColumns, serverSideIteratorList, serverSideIteratorOptions
+

+ +

+ + +
Constructor Summary
+ + + + + + + + +
Constructors
Constructor and Description
ClientSideIteratorScanner(Scanner scanner) +
Constructs a scanner that can execute client-side iterators.
+
+

Constructors
Constructor and Description
`ClientSideIteratorScanner(Scanner scanner)` + Constructs a scanner that can execute client-side iterators. +

+ +

+ + +

Method Summary

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Methods
Modifier and Type	Method and Description
`void`	`disableIsolation()` + Disables row isolation. +
`void`	`enableIsolation()` + Enables row isolation. +
`int`	`getBatchSize()` + Returns the batch size (number of Key/Value pairs) that will be fetched at a time from a tablet server. +
`Range`	`getRange()` + Returns the range of keys to scan over. +
`int`	`getTimeOut()` + Returns the setting for how long a scanner will automatically retry when a failure occurs. +
`Iterator<Map.Entry<Key,Value>>`	`iterator()` + Returns an iterator over an accumulo table. +
`void`	`setBatchSize(int size)` + Sets the number of Key/Value pairs that will be fetched at a time from a tablet server. +
`void`	`setRange(Range range)` + Sets the range of keys to scan over. +
`void`	`setSource(Scanner scanner)` + Sets the source Scanner. +
`void`	`setTimeOut(int timeOut)` + This setting determines how long a scanner will automatically retry when a failure occurs. +

+ + +
Methods inherited from class org.apache.accumulo.core.client.impl.ScannerOptions
+addScanIterator, clearColumns, clearScanIterators, fetchColumn, fetchColumn, fetchColumnFamily, getFetchedColumns, removeScanIterator, setColumnFamilyRegex, setColumnQualifierRegex, setOptions, setRowRegex, setScanIteratorOption, setScanIterators, setupRegex, setValueRegex, updateScanIteratorOption

+ + +
Methods inherited from class java.lang.Object
+clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

+ + +
Methods inherited from interface org.apache.accumulo.core.client.ScannerBase
+addScanIterator, clearColumns, clearScanIterators, fetchColumn, fetchColumnFamily, removeScanIterator, setColumnFamilyRegex, setColumnQualifierRegex, setRowRegex, setScanIteratorOption, setScanIterators, setupRegex, setValueRegex, updateScanIter atorOption

+ +
- + + +
  Constructor Detail
  + + + +
  - +
    ClientSideIteratorScanner
    +
```
public ClientSideIteratorScanner(Scanner scanner)
```
    +
    Constructs a scanner that can execute client-side iterators.
    +
    Parameters:
    scanner - the source scanner
    +
  +
+ +
- + + +
  Method Detail
  + + + +
  - +
    setSource
    +
```
public void setSource(Scanner scanner)
```
    +
    Sets the source Scanner.
    +
    Parameters:
    scanner -
    +
  + + + +
  - +
    iterator
    +
```
public Iterator<Map.Entry<Key,Value>> iterator()
```
    +
    Description copied from interface: ScannerBase
    +
    Returns an iterator over an accumulo table. This iterator uses the options that are currently set for its lifetime, so setting options will have no effect + on existing iterators. + + Keys returned by the iterator are not guaranteed to be in sorted order.
    +
    +
    Specified by:
    +
    iterator in interface Iterable<Map.Entry<Key,Value>>
    +
    Specified by:
    +
    iterator in interface ScannerBase
    +
    Overrides:
    +
    iterator in class org.apache.accumulo.core.client.impl.ScannerOptions
    +
    Returns:
    an iterator over Key,Value pairs which meet the restrictions set on the scanner
    +
  + + + +
  - +
    setTimeOut
    +
```
public void setTimeOut(int timeOut)
```
    +
    Description copied from interface: Scanner
    +
    This setting determines how long a scanner will automatically retry when a failure occurs. By default a scanner will retry forever.
    +
    +
    Specified by:
    +
    setTimeOut in interface Scanner
    +
    Parameters:
    timeOut - in seconds
    +
  + + + +
  - +
    getTimeOut
    +
```
public int getTimeOut()
```
    +
    Description copied from interface: Scanner
    +
    Returns the setting for how long a scanner will automatically retry when a failure occurs.
    +
    +
    Specified by:
    +
    getTimeOut in interface Scanner
    +
    Returns:
    the timeout configured for this scanner
    +
  + + + +
  - +
    setRange
    +
```
public void setRange(Range range)
```
    +
    Description copied from interface: Scanner
    +
    Sets the range of keys to scan over.
    +
    +
    Specified by:
    +
    setRange in interface Scanner
    +
    Parameters:
    range - key range to begin and end scan
    +
  + + + +
  - +
    getRange
    +
```
public Range getRange()
```
    +
    Description copied from interface: Scanner
    +
    Returns the range of keys to scan over.
    +
    +
    Specified by:
    +
    getRange in interface Scanner
    +
    Returns:
    the range configured for this scanner
    +
  + + + +
  - +
    setBatchSize
    +
```
public void setBatchSize(int size)
```
    +
    Description copied from interface: Scanner
    +
    Sets the number of Key/Value pairs that will be fetched at a time from a tablet server.
    +
    +
    Specified by:
    +
    setBatchSize in interface Scanner
    +
    Parameters:
    size - the number of Key/Value pairs to fetch per call to Accumulo
    +
  + + + +
  - +
    getBatchSize
    +
```
public int getBatchSize()
```
    +
    Description copied from interface: Scanner
    +
    Returns the batch size (number of Key/Value pairs) that will be fetched at a time from a tablet server.
    +
    +
    Specified by:
    +
    getBatchSize in interface Scanner
    +
    Returns:
    the batch size configured for this scanner
    +
  + + + +
  - +
    enableIsolation
    +
```
public void enableIsolation()
```
    +
    Description copied from interface: Scanner
    +
    Enables row isolation. Writes that occur to a row after a scan of that row has begun will not be seen if this option is enabled.
    +
    +
    Specified by:
    +
    enableIsolation in interface Scanner
    +
    +
  + + + +
  - +
    disableIsolation
    +
```
public void disableIsolation()
```
    +
    Description copied from interface: Scanner
    +
    Disables row isolation. Writes that occur to a row after a scan of that row has begun may be seen if this option is enabled.
    +
    +
    Specified by:
    +
    disableIsolation in interface Scanner
    +
    +
  +
+

Class ClientSideIteratorScanner.ScannerTranslator

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

scanner

Constructor Detail

ClientSideIteratorScanner.ScannerTranslator

Method Detail

init

hasTop

next

seek

getTopKey

getTopValue

deepCopy

Class ClientSideIteratorScanner

Nested Class Summary

Field Summary

Fields inherited from class org.apache.accumulo.core.client.impl.ScannerOptions

Constructor Summary

Method Summary

Methods inherited from class org.apache.accumulo.core.client.impl.ScannerOptions

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.accumulo.core.client.ScannerBase

Constructor Detail

ClientSideIteratorScanner

Method Detail

setSource

iterator

setTimeOut

getTimeOut

setRange

getRange

setBatchSize

getBatchSize

enableIsolation

disableIsolation