Package convex.core.data

Class StringShort

java.lang.Object

convex.core.data.AObject

convex.core.data.ACell

convex.core.data.ACountable<CVMChar>

convex.core.data.ABlobLike<CVMChar>

convex.core.data.AString

convex.core.data.StringShort

All Implemented Interfaces:

IValidated, IWriteable, Comparable<ABlobLike<?>>

public final class StringShort
extends AString

Class representing a short CVM string, backed by a flat Blob Used for most small strings, and acts as the leaf chunk for StringTrees

Field Summary

Fields

Modifier and Type	Field	Description
static final StringShort	EMPTY	The canonical empty String
static final int	MAX_EMBEDDED_STRING_LENGTH	Length of longest StringShort value that is embedded Basically max embedded length minus tag byte and 2-byte length
static final int	MAX_ENCODING_LENGTH
static final int	MAX_LENGTH	Length of longest StringShort value in bytes.

Fields inherited from class convex.core.data.AString

length

Fields inherited from class convex.core.data.ACell

cachedRef, memorySize

Fields inherited from class convex.core.data.AObject

encoding

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StringShort(byte[] data)
protected	StringShort(byte[] data, int offset, int length)
protected	StringShort(Blob data)

Method Summary

Modifier and Type	Method	Description
byte	byteAt(long index)	Gets a byte at the specified index.
int	compareTo(ABlobLike<?> o)
static StringShort	create(AArrayBlob b)	Creates a StringShort instance from a Blob of UTF-8 data.
static StringShort	create(String string)	Creates a StringShort instance from a regular Java String
int	encodeRaw(byte[] bs, int pos)	Encode the data of this String.
boolean	equals(AString b)	Checks for equality between two strings.
final boolean	equals(StringShort a)
boolean	equalsBytes(ABlob b)	Compare the byte content of this BlobLike to a Blob value
int	estimatedEncodingSize()	Estimate the encoded data size for this Cell.
<R extends ACell> Ref<R>	getRef(int i)	Gets a numbered child Ref from within this Cell.
int	getRefCount()	Gets the number of Refs contained within this Cell.
int	intAt(long index)	Gets 32 bytes integer at given position.
boolean	isCanonical()	Returns true if this Cell is in a canonical representation.
final boolean	isCVMValue()	Returns true if this cell is a first class CVM Value allowable in the CVM state Sub-structural cells that are not themselves first class values should return false Records and types that are not permissible on the CVM should return false.
boolean	isEmbedded()	Determines if this Cell Represents an embedded object.
long	longValue()	Converts this BlobLike to the corresponding long value.
protected void	printEscaped(BlobBuilder sb, long start, long end)	Prints this string as escaped UTF-8
static StringShort	read(long length, Blob blob, int pos)	Read a StringShort from an encoding.
AString	slice(long start, long end)	Gets a slice of this string, or null if not a valid slice
Blob	toBlob()	Converts this String to an equivalent Blob representation.
AString	toCanonical()	Converts this Cell to a canonical version.
String	toString()	Returns the Java String representation of this Cell.
ACell	updateRefs(IRefFunction func)	Updates all Refs in this object using the given function.
void	validateCell()	Validates the local structure and invariants of this cell.
int	writeRawData(byte[] bs, int pos)	Write the raw UTF-8 data of this String to a byte array.

Methods inherited from class convex.core.data.AString

append, append, charAt, count, empty, encode, equals, get, getBytes, getElementRef, getTag, getType, hashCode, hexMatch, print, split, toCVMString

Methods inherited from class convex.core.data.ABlobLike

appendHex, byteAtUnchecked, getBytes, getHexDigit, hexEquals, hexLength, hexMatch, isDataValue, toFlatBlob, toHexString, toHexString

Methods inherited from class convex.core.data.ACountable

isEmpty, size, slice

Methods inherited from class convex.core.data.ACell

attachMemorySize, attachRef, cachedEncoding, cachedHash, calcMemorySize, createEncoding, createRef, equals, genericEquals, getCanonical, getChildRefs, getEncoding, getEncodingLength, getHash, getMemorySize, getMemorySize, getRef, validate

Methods inherited from class convex.core.data.AObject

attachEncoding, print, print

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

MAX_EMBEDDED_STRING_LENGTH

public static final int MAX_EMBEDDED_STRING_LENGTH

Length of longest StringShort value that is embedded Basically max embedded length minus tag byte and 2-byte length

See Also:

• Constant Field Values

MAX_LENGTH

public static final int MAX_LENGTH

Length of longest StringShort value in bytes. Use Blob as base.

See Also:

• Constant Field Values

MAX_ENCODING_LENGTH

public static final int MAX_ENCODING_LENGTH

EMPTY

public static final StringShort EMPTY

The canonical empty String

Constructor Details

StringShort

protected StringShort(Blob data)

StringShort

protected StringShort(byte[] data)

StringShort

protected StringShort(byte[] data,
 int offset,
 int length)

Method Details

create

public static StringShort create(String string)

Creates a StringShort instance from a regular Java String

Parameters:

string - String to wrap as StringShort

Returns:

StringShort instance, or null if String is of invalid size

create

public static StringShort create(AArrayBlob b)

Creates a StringShort instance from a Blob of UTF-8 data. Shares underlying array.

Parameters:

b - Array Blob to convert to StringShort

Returns:

StringShort instance

byteAt

public byte byteAt(long index)

Description copied from class: AString

Gets a byte at the specified index. Returns -1 (0xff) if outside String.

Specified by:

byteAt in class AString

Parameters:

index - Index into String (byte position)

Returns:

Raw byte value

intAt

public int intAt(long index)

Description copied from class: AString

Gets 32 bytes integer at given position. Extends with 255 (invalid UTF-8) if needed. The main purpose of this function is to enable fast peeking at UTF-8 characters

Overrides:

intAt in class AString

Parameters:

index - Index into String (byte position)

Returns:

Raw integer value

validateCell

public void validateCell()
                  throws InvalidDataException

Description copied from class: ACell

Validates the local structure and invariants of this cell. Called by validate() super implementation. Should validate directly contained data, but should not validate all other structure of this cell. In particular, should not traverse potentially missing child Refs.

Specified by:

validateCell in class ACell

Throws:

InvalidDataException - If the Cell is invalid

encodeRaw

public int encodeRaw(byte[] bs,
 int pos)

Description copied from class: AString

Encode the data of this String. Assumes tag already written

Specified by:

encodeRaw in class AString

Parameters:

bs - A byte array to which to write the encoding

pos - The offset into the byte array

Returns:

New position after writing

writeRawData

public int writeRawData(byte[] bs,
 int pos)

Description copied from class: AString

Write the raw UTF-8 data of this String to a byte array.

Specified by:

writeRawData in class AString

Parameters:

bs - Destination byte array

pos - Position in target array to write to

Returns:

End position in array after writing

estimatedEncodingSize

public int estimatedEncodingSize()

Description copied from interface: IWriteable

Estimate the encoded data size for this Cell. Used for quickly sizing buffers. Implementations should try to return a size that is highly likely to contain the entire object when encoded, including the tag byte. Should not traverse soft Refs, i.e. must be usable on arbitrary partial data structures

Returns:

The estimated size for the binary representation of this object.

isCanonical

public boolean isCanonical()

Description copied from class: ACell

Returns true if this Cell is in a canonical representation. Non-canonical objects may be used on a temporary internal basis, they should be converted to canonical representations for general purpose use.

Specified by:

isCanonical in class ACell

Returns:

true if the object is in canonical format, false otherwise

isCVMValue

public final boolean isCVMValue()

Description copied from class: ACell

Returns true if this cell is a first class CVM Value allowable in the CVM state Sub-structural cells that are not themselves first class values should return false Records and types that are not permissible on the CVM should return false. Pretty much everything else should return true. Note: CVM values might not be in a canonical format, e.g. temporary data structures

Specified by:

isCVMValue in class ACell

Returns:

true if the object is a CVM Value, false otherwise

isEmbedded

public boolean isEmbedded()

Description copied from class: ACell

Determines if this Cell Represents an embedded object. Embedded objects are encoded directly into the encoding of the containing Cell (avoiding the need for a hashed reference). Subclasses should override this if they have a cheap O(1) way to determine if they are embedded or otherwise.

Overrides:

isEmbedded in class ACell

Returns:

true if Cell is embedded, false otherwise

getRef

public <R extends ACell> Ref<R> getRef(int i)

Description copied from class: ACell

Gets a numbered child Ref from within this Cell. WARNING: May need to convert to a canonical instance

Overrides:

getRef in class ACell

Type Parameters:

R - Type of referenced Cell

Parameters:

i - Index of ref to get

Returns:

The Ref at the specified index

updateRefs

public ACell updateRefs(IRefFunction func)

Description copied from class: ACell

Updates all Refs in this object using the given function. The function *must not* change the hash value of Refs, in order to ensure structural integrity of modified data structures. The implementation *should* re-attach any original encoding in order to prevent re-encoding or surplus hashing This is a building block for a very sneaky trick that enables use to do a lot of efficient operations on large trees of smart references. Must return the same object if no Refs are altered.

Overrides:

updateRefs in class ACell

Parameters:

func - Ref update function

Returns:

Cell with updated Refs

getRefCount

public int getRefCount()

Description copied from class: ACell

Gets the number of Refs contained within this Cell. This number is final / immutable for any given instance and is defined by the Cell encoding rules. Contained Refs may be either external or embedded.

Overrides:

getRefCount in class ACell

Returns:

The number of Refs in this Cell

read

public static StringShort read(long length,
 Blob blob,
 int pos)

Read a StringShort from an encoding. Assumes tag and length already validated.

Parameters:

length - Length of string in UTF-8 bytes

blob - Source of encoding

pos - Position of encoding start (i.e. tag)

Returns:

String instance

toBlob

public Blob toBlob()

Description copied from class: AString

Converts this String to an equivalent Blob representation. Must round trip all values.

Specified by:

toBlob in class AString

Returns:

Blob representation of UTF-8 String

equals

public boolean equals(AString b)

Description copied from class: AString

Checks for equality between two strings. Should be optimised

Specified by:

equals in class AString

Parameters:

b - Other string (may be null)

Returns:

True if strings are exactly equal, false otherwise

equals

public final boolean equals(StringShort a)

compareTo

public int compareTo(ABlobLike<?> o)

Specified by:

compareTo in interface Comparable<ABlobLike<?>>

Specified by:

compareTo in class ABlobLike<CVMChar>

toCanonical

public AString toCanonical()

Description copied from class: ACell

Converts this Cell to a canonical version. Must return this Cell if already canonical, may be O(n) in size of value otherwise. Callers should usually use getCanonical(), which caches canonical instances once created

Specified by:

toCanonical in class AString

Returns:

Canonical version of Cell

slice

public AString slice(long start,
 long end)

Description copied from class: AString

Gets a slice of this string, or null if not a valid slice

Specified by:

slice in class AString

Parameters:

start - Start index (inclusive)

end - End index (Exclusive)

Returns:

Specified substring

printEscaped

protected void printEscaped(BlobBuilder sb,
 long start,
 long end)

Description copied from class: AString

Prints this string as escaped UTF-8

Specified by:

printEscaped in class AString

Parameters:

sb -

equalsBytes

public boolean equalsBytes(ABlob b)

Description copied from class: ABlobLike

Compare the byte content of this BlobLike to a Blob value

Specified by:

equalsBytes in class ABlobLike<CVMChar>

Parameters:

b - Blob value to compare with

Returns:

`true` if byte contents are exactly equal, `false` otherwise

longValue

public long longValue()

Description copied from class: ABlobLike

Converts this BlobLike to the corresponding long value. Assumes big-endian format, as if the entire blob is interpreted as an unsigned big integer. Higher bytes outside the Long range will be ignored, i.e. the lowest 64 bits are taken

Specified by:

longValue in class ABlobLike<CVMChar>

Returns:

long value of this blob

toString

public String toString()

Description copied from class: ACell

Returns the Java String representation of this Cell. The String representation is intended to be a easy-to-read textual representation of the Cell's data content.

Overrides:

toString in class AString