scalax.io

Seekable

trait Seekable extends Input with Output

An object for reading and writing to Random Access IO objects such as Files.

In addition to the methods contributed by Input and Output patch, insert and append are provided as more random access style operations.

Note: The methods in Output are always fully destructive. IE write will replace all data in the file, insert, patch or append are your friends if that is not the behaviour you want.

Self Type
Seekable
Since

1.0

Linear Supertypes
Output, Input, AnyRef, Any
Known Subclasses
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  1. Seekable
  2. Output
  3. Input
  4. AnyRef
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Visibility
  1. Public
  2. All

Abstract Value Members

  1. def size : Option[Long]

    The number of bytes that can be read from the underlying resource.

    The number of bytes that can be read from the underlying resource.

    if length == None then it is not possible to determine the number of bytes in advance.

    Attributes
    abstract
    Definition Classes
    Input
  2. def underlyingChannel (append: Boolean): OpenedResource[SeekableByteChannel]

    Attributes
    protected abstract

Concrete Value Members

  1. def != (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  2. def != (arg0: Any): Boolean

    Attributes
    final
    Definition Classes
    Any
  3. def ## (): Int

    Attributes
    final
    Definition Classes
    AnyRef → Any
  4. def == (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  5. def == (arg0: Any): Boolean

    Attributes
    final
    Definition Classes
    Any
  6. def append (string: String)(implicit codec: Codec = Codec.default): Unit

    Append a string to the end of the Seekable object.

    Append a string to the end of the Seekable object.

    string

    the data to write

    codec

    the codec of the string to be written. The string will be converted to the encoding of codec

  7. def append [T] (data: T)(implicit converter: OutputConverter[T]): Unit

    Append bytes to the end of a file

    Append bytes to the end of a file

    Important: The use of an Array is highly recommended because normally arrays can be more efficiently written using the underlying APIs

    data

    The data to write. This can be any type that has a OutputConverter associated with it. There are predefined $outputConverters for several types. See the OutputConverter object for the predefined types and for objects to simplify implementing custom OutputConverter

    $converterParam

  8. def appendChannel [U] (f: (SeekableByteChannel) ⇒ U): U

    Attributes
    protected
  9. def appendIntsAsBytes (data: Int*): Unit

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes.

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes. In other words just taking the first byte. This is pretty common in Java.io style IO. IE

     outputStream.write(1) 
    

    1 is written as a single byte.

  10. def appendStrings (strings: Traversable[String], separator: String = "")(implicit codec: Codec = Codec.default): Unit

    Append several strings to the end of the Seekable object.

    Append several strings to the end of the Seekable object.

    strings

    The strings to write

    separator

    A string to add between each string. It is not added to the before the first string or after the last.

    codec

    The codec of the strings to be written. The strings will be converted to the encoding of codec

  11. def asInstanceOf [T0] : T0

    Attributes
    final
    Definition Classes
    Any
  12. def blocks (blockSize: Option[Int] = None): LongTraversable[ByteBlock]

    Read the input as blocks of bytes.

    Read the input as blocks of bytes. This method should be avoided unless the maximum performance is absolutely required because bytes provides very good performance and is a better API for most applications.

    However since it better reflects how data is read with most input sources (like InputStreams and ReadableByteChannels); blocks is slightly more performance than bytes and therefore can be used when performance is the most important consideration.

    blockSize

    block size can optionally be specified but the default is normally acceptable.

    Definition Classes
    SeekableInput
  13. def byteArray : Array[Byte]

    This method aspires to be the fastest way to read a stream of known length into memory.

    This method aspires to be the fastest way to read a stream of known length into memory.

    Definition Classes
    Input
  14. def bytes : LongTraversable[Byte]

    Obtains a Traversable for conveniently processing the resource as bytes.

    Obtains a Traversable for conveniently processing the resource as bytes.

    returns

    an non-strict traversable over all the bytes

    Definition Classes
    SeekableInput
  15. def bytesAsInts : LongTraversable[Int]

    Obtains a Traversable for conveniently processing the file as Ints.

    Obtains a Traversable for conveniently processing the file as Ints.

    returns

    an non-strict traversable over all the bytes with the bytes being represented as Ints

    Definition Classes
    SeekableInput
  16. def chars (implicit codec: Codec): LongTraversable[Char]

    The characters in the object.

    The characters in the object.

    If the codec is not the same as the source codec (the codec of the underlying data) then the characters will converted to the desired codec.

    codec

    The codec representing the desired encoding of the characters @return an traversable of all the characters

    Definition Classes
    SeekableInput
  17. def clone (): AnyRef

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  18. def copyDataTo (output: Output): Unit

    Copy all data from this Input object to the Output object as efficiently as possible.

    Copy all data from this Input object to the Output object as efficiently as possible.

    output

    output sink to copy the data to

    Definition Classes
    Input
  19. def doCopyFrom (input: Input): Unit

    If possible efficiently copy data from input.

    If possible efficiently copy data from input. It MUST NOT forward request to input's copyTo method because that could trigger an infinate loop

    Attributes
    protected
    Definition Classes
    Output
  20. def eq (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  21. def equals (arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  22. def finalize (): Unit

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  23. def getClass (): java.lang.Class[_]

    Attributes
    final
    Definition Classes
    AnyRef → Any
  24. def hashCode (): Int

    Definition Classes
    AnyRef → Any
  25. def insert [T] (position: Long, data: T)(implicit converter: OutputConverter[T]): Any

    Inserts data at a position in the Seekable.

    Inserts data at a position in the Seekable. The actual position in the Seekable where the data is inserted depends on the type of data being written. For example if Longs are being written then position calculated as position * 8

    Important: The use of an Array is highly recommended because normally arrays can be more efficiently written using the underlying APIs

    position

    The position where the data is inserted into the Seekable. The actual position in the Seekable where the data is inserted depends on the type of data being written. For example if Longs are being written then position calculated as position * 8

    data

    The data to write. This can be any type that has a OutputConverter associated with it. There are predefined $outputConverters for several types. See the OutputConverter object for the predefined types and for objects to simplify implementing custom OutputConverter

    $converterParam

  26. def insert (position: Long, string: String)(implicit codec: Codec = Codec.default): Unit

    Inserts a string at a position in the Seekable.

    Inserts a string at a position in the Seekable. This is a potentially inefficient because of the need to count characters. If the codec is not a fixed sized codec (for example UTF8) each character must be converted in the file up to the point of insertion.

    position

    The position in the file to perform the insert. A position of 2 will insert the character after the second character (not byte).

    string

    The string that will be inserted into the Seekable

    codec

    The codec to use for determining the location for inserting the string and for encoding the string as bytes

  27. def insertIntsAsBytes (position: Long, data: Int*): Any

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes.

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes. In other words just taking the first byte. This is pretty common in Java.io style IO. IE

     outputStream.write(1) 
    

    1 is written as a single byte.

  28. def isInstanceOf [T0] : Boolean

    Attributes
    final
    Definition Classes
    Any
  29. def lines (terminator: Terminator = Terminators.Auto, includeTerminator: Boolean = false)(implicit codec: Codec = Codec.default): LongTraversable[String]

    Obtain an non-strict traversable for iterating through the lines in the object

    Obtain an non-strict traversable for iterating through the lines in the object

    If the codec is not the same as the source codec (the codec of the underlying data) then the characters will converted to the desired codec.

    terminator

    The strategy for determining the end of line Default is to auto-detect the EOL

    includeTerminator

    if true then the line will end with the line terminator Default is false

    @return a non-strict traversable for iterating through all the lines

    codec

    The codec representing the desired encoding of the characters

    Definition Classes
    Input
  30. def ne (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  31. def notify (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
  32. def notifyAll (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
  33. def open [U] (f: (OpenSeekable) ⇒ U): U

    Execute the function 'f' passing an Seekable instance that performs all operations on a single opened connection to the underlying resource.

    Execute the function 'f' passing an Seekable instance that performs all operations on a single opened connection to the underlying resource. Typically each call to one of the Seekable's methods results in a new connection. For example if write it called typically it will write to the start of the seekable but in open it will write to the current position.

    Even if the underlying resource is an appending, using open will be more efficient since the connection only needs to be made a single time.

    f

    the function to execute on the new Output instance (which uses a single connection)

    returns

    the result of the function

  34. def openOutput [U] (f: (Output) ⇒ U): U

    Execute the function 'f' passing an Output instance that performs all operations on a single opened connection to the underlying resource.

    Execute the function 'f' passing an Output instance that performs all operations on a single opened connection to the underlying resource. Typically each call to one of the Output's methods results in a new connection. For example if the underlying OutputStream truncates the file each time the connection is made then calling write two times will result in the contents of the second write overwriting the second write.

    Even if the underlying resource is an appending, using open will be more efficient since the connection only needs to be made a single time.

    f

    the function to execute on the new Output instance (which uses a single connection)

    returns

    the result of the function

    Definition Classes
    Output
  35. def patch [T] (position: Long, data: T, overwrite: Overwrite)(implicit converter: OutputConverter[T]): Unit

    Update a portion of the file content at the declared location.

    Update a portion of the file content at the declared location. This is the most flexible of the random access methods but is also (probably) the trickiest to fully understand. That said it behaves (almost) identical to a scala.collection.Seq.patch method, so if you understand that you should not have difficulty understanding this method.

    Important: The use of an Array is highly recommended because normally arrays can be more efficiently written using the underlying APIs

    To append data the position must >= size

    If the position is within the file but the position + bytes.length is beyond the end of the file the file will be enlarged so that the entire string can fit in the file

    The write begins at the position indicated. So if position = 0 then the write will begin at the first byte of the file.

    position

    The start position of the update starting at 0. The position must be within the file or == size (for appending)

    data

    The data to write. This can be any type that has a OutputConverter associated with it. There are predefined $outputConverters for several types. See the OutputConverter object for the predefined types and for objects to simplify implementing custom OutputConverter

    overwrite

    The strategy that dictates how many characters/bytes/units are overwritten $converterParam

  36. def patch (position: Long, string: String, overwrite: Overwrite)(implicit codec: Codec = Codec.default): Unit

    Update a portion of the file content at the declared location.

    Update a portion of the file content at the declared location. This is the most flexible of the random access methods but is also (probably) the trickiest to fully understand. That said it behaves (almost) identical to a scala.collection.Seq.patch method, so if you understand that you should not have difficulty understanding this method.

    If the position is beyond the end of the file a BufferUnderflow Exception will be thrown

    If the position is within the file but the position + string.getBytes(codec).length is beyond the end of the file the file will be enlarged so that the entire string can fit in the file

    The write begins at the position indicated. So if position = 0 then the write will begin at the first byte of the file.

    position

    The start position of the update starting at 0. The position is the position'th character in the file using the codec for decoding the file The position must be within the file.

    string

    The string to write to the file starting at position.

    overwrite

    The strategy that dictates how many characters/bytes/units are overwritten

    codec

    The codec to use for decoding the underlying data into characters

  37. def patchIntsAsBytes (position: Long, overwrite: Overwrite, data: Int*): Unit

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes.

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes. In other words just taking the first byte. This is pretty common in Java.io style IO. IE

     outputStream.write(1) 
    

    1 is written as a single byte.

  38. def readWriteChannel [U] (f: (SeekableByteChannel) ⇒ U): U

    Attributes
    protected
  39. def slurpString (implicit codec: Codec = Codec.default): String

    Loads all the characters into memory.

    Loads all the characters into memory. There is no protection against loading very large files/amounts of data.

    codec

    The codec representing the desired encoding of the characters

    Definition Classes
    Input
  40. def synchronized [T0] (arg0: ⇒ T0): T0

    Attributes
    final
    Definition Classes
    AnyRef
  41. def tempFile (): Input with Output

    Create a temporary file to use for performing certain operations.

    Create a temporary file to use for performing certain operations. It should be as efficient as possible to copy from the temporary file to this Seekable and vice-versa. Can be overridden for performance

    Attributes
    protected
  42. def toString (): String

    Definition Classes
    AnyRef → Any
  43. def truncate (position: Long): Unit

    Truncate/Chop the Seekable to the number of bytes declared by the position param

  44. def truncateString (position: Long)(implicit codec: Codec = Codec.default): Unit

  45. def underlyingOutput : OutputResource[OutputStream]

    Attributes
    protected
    Definition Classes
    SeekableOutput
  46. def wait (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  47. def wait (arg0: Long, arg1: Int): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  48. def wait (arg0: Long): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  49. def write (string: String)(implicit codec: Codec = Codec.default): Unit

    Writes a string.

    Writes a string.

    string

    the data to write

    codec

    the codec of the string to be written. The string will be converted to the encoding of sourceCodec Default is sourceCodec

    Definition Classes
    Output
  50. def write [T] (data: T)(implicit writer: OutputConverter[T]): Unit

    Write data to the underlying object.

    Write data to the underlying object. Each time write is called the resource is reopened, in the case of a file this means that the file will be opened and truncated. The

    In the case of writing ints and bytes it is often recommended to write arrays of data since normally the underlying object can write arrays of bytes or integers most efficiently.

    Since Characters require a codec to write to an OutputStream characters cannot be written with this method unless a OutputWriterFunction.CharFunction object is provided as the writer.

    data

    The data to write to underlying object. Any data that has a resolvable OutputConverter can be written. See the OutputConverter object for the defined OutputConverter implementations and classes to assist implementing more.

    writer

    The strategy used to write the data to the underlying object. Many standard data-types are implicitly resolved and do not need to be supplied

    Definition Classes
    Output
    See also

    #writeChars for more on writing characters

  51. def writeChars (characters: TraversableOnce[Char])(implicit codec: Codec = Codec.default): Unit

    Definition Classes
    Output
  52. def writeIntsAsBytes (data: Int*): Unit

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes.

    Since the OutputConverter object defined for writing Ints encodes Ints using 4 bytes this method is provided to simply write an array of Ints as if they are Bytes. In other words just taking the first byte. This is pretty common in Java.io style IO. IE

     outputStream.write(1) 
    

    1 is written as a single byte.

    Definition Classes
    Output
  53. def writeStrings (strings: Traversable[String], separator: String = "")(implicit codec: Codec = Codec.default): Unit

    Write several strings.

    Write several strings.

    strings

    The data to write

    separator

    A string to add between each string. It is not added to the before the first string or after the last.

    codec

    The codec of the strings to be written. The strings will be converted to the encoding of sourceCodec

    Definition Classes
    Output

Inherited from Output

Inherited from Input

Inherited from AnyRef

Inherited from Any