o != arg0
is the same as !(o == (arg0))
.
o != arg0
is the same as !(o == (arg0))
.
the object to compare against this object for dis-equality.
false
if the receiver object is equivalent to the argument; true
otherwise.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
o == arg0
is the same as o.equals(arg0)
.
o == arg0
is the same as o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
Append an entry for the given offset/location pair to the index.
Append an entry for the given offset/location pair to the index. This entry must have a larger offset than all subsequent entries.
This method is used to cast the receiver object to be of type T0
.
This method is used to cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression1.asInstanceOf[String]
will throw a ClassCastException
at runtime, while the expressionList(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as
part of compilation it is not possible to check whether the contents of the list are of the requested typed.
the receiver object.
This method creates and returns a copy of the receiver object.
This method creates and returns a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
Close the index
Close the index
Delete this index file
Delete this index file
The number of entries in this index
The number of entries in this index
Get the nth offset mapping from the index
Get the nth offset mapping from the index
The entry number in the index
The offset/position pair at that entry
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
The eq
method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on
non-null instances of AnyRef
:
* It is reflexive: for any non-null instance x
of type AnyRef
, x.eq(x)
returns true
.
* It is symmetric: for any non-null instances x
and y
of type AnyRef
, x.eq(y)
returns true
if and
only if y.eq(x)
returns true
.
* It is transitive: for any non-null instances x
, y
, and z
of type AnyRef
if x.eq(y)
returns true
and y.eq(z)
returns true
, then x.eq(z)
returns true
.
Additionally, the eq
method has three other properties.
* It is consistent: for any non-null instances x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.
* For any non-null instance x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.
* null.eq(null)
returns true
.
When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
the object to compare against this object for reference equality.
true
if the argument is a reference to the receiver object; false
otherwise.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence
relation]:
* It is reflexive: for any instance x
of type Any
, x.equals(x)
should return true
.
* It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and
only if y.equals(x)
returns true
.
* It is transitive: for any instances x
, y
, and z
of type AnyRef
if x.equals(y)
returns true
and
y.equals(z)
returns true
, then x.equals(z)
should return true
.
If you override this method, you should verify that your implementation remains an equivalence relation.
Additionally, when overriding this method it is often necessary to override hashCode
to ensure that objects
that are "equal" (o1.equals(o2)
returns true
) hash to the same
scala.Int
(o1.hashCode.equals(o2.hashCode)
).
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
The details of when and if the finalize
method are invoked, as well as the interaction between finalize
and non-local returns and exceptions, are all platform dependent.
Flush the data in the index to disk
Flush the data in the index to disk
Returns a representation that corresponds to the dynamic class of the receiver object.
Returns a representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
Returns a hash code value for the object.
Returns a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet
not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
.
However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals
method.
the hash code value for the object.
True iff there are no more slots available in this index
True iff there are no more slots available in this index
This method is used to test whether the dynamic type of the receiver object is T0
.
This method is used to test whether the dynamic type of the receiver object is T0
.
Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.isInstanceOf[String]
will return false
, while the expression List(1).isInstanceOf[List[String]]
will
return true
. In the latter example, because the type argument is erased as part of compilation it is not
possible to check whether the contents of the list are of the requested typed.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Find the largest offset less than or equal to the given targetOffset and return a pair holding this offset and it's corresponding physical file position.
Find the largest offset less than or equal to the given targetOffset and return a pair holding this offset and it's corresponding physical file position.
The offset to look up.
The offset found and the corresponding file position for this offset. If the target offset is smaller than the least entry in the index (or the index is empty), the pair (baseOffset, 0) is returned.
The maximum number of eight-byte entries this index can hold
The maximum number of eight-byte entries this index can hold
o.ne(arg0)
is the same as !(o.eq(arg0))
.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
the object to compare against this object for reference dis-equality.
false
if the argument is not a reference to the receiver object; true
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
The last entry in the index
The last entry in the index
Rename the file that backs this offset index
Rename the file that backs this offset index
true iff the rename was successful
Reset the size of the memory map and the underneath file.
Reset the size of the memory map and the underneath file. This is used in two kinds of cases: (1) in trimToValidSize() which is called at closing the segment or new segment being rolled; (2) at loading segments from disk or truncating back to an old segment where a new log segment became active; we want to reset the index size to maximum index size to avoid rolling new segment.
Do a basic sanity check on this index to detect obvious problems
Do a basic sanity check on this index to detect obvious problems
The number of bytes actually used by this index
The number of bytes actually used by this index
Returns a string representation of the object.
Returns a string representation of the object.
The default representation is platform dependent.
a string representation of the object.
Trim this segment to fit just the valid entries, deleting all trailing unwritten bytes from the file.
Trim this segment to fit just the valid entries, deleting all trailing unwritten bytes from the file.
Truncate the entire index, deleting all entries
Truncate the entire index, deleting all entries
Remove all entries from the index which have an offset greater than or equal to the given offset.
Remove all entries from the index which have an offset greater than or equal to the given offset. Truncating to an offset larger than the largest in the index has no effect.
An index that maps offsets to physical file locations for a particular log segment. This index may be sparse: that is it may not hold an entry for all messages in the log.
The index is stored in a file that is pre-allocated to hold a fixed maximum number of 8-byte entries.
The index supports lookups against a memory-map of this file. These lookups are done using a simple binary search variant to locate the offset/location pair for the greatest offset less than or equal to the target offset.
Index files can be opened in two ways: either as an empty, mutable index that allows appends or an immutable read-only index file that has previously been populated. The makeReadOnly method will turn a mutable file into an immutable one and truncate off any extra bytes. This is done when the index file is rolled over.
No attempt is made to checksum the contents of this file, in the event of a crash it is rebuilt.
The file format is a series of entries. The physical format is a 4 byte "relative" offset and a 4 byte file location for the message with that offset. The offset stored is relative to the base offset of the index file. So, for example, if the base offset was 50, then the offset 55 would be stored as 5. Using relative offsets in this way let's us use only 4 bytes for the offset.
The frequency of entries is up to the user of this class.
All external APIs translate from relative offsets to full offsets, so users of this class do not interact with the internal storage format.