Memory
interface Memory
Fields
Methods
lock
abstract suspend fun <T> lock(block: suspend Memory.()->T): T
Runs the block within a thread-safe mutual exclusion.
Parameters
| Name | Description |
|---|---|
block: suspend Memory.()->T
|
ReturnValue
| Name | Description |
|---|---|
T
|
readInt
abstract fun readInt(offset: Int, byteWidth: Int, alignment: Int): Int
Reads an Int from the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
offset: Int
|
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byteWidth: Int
|
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alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Int
|
readUInt
abstract fun readUInt(offset: Int, byteWidth: Int, alignment: Int): UInt
Parameters
| Name | Description |
|---|---|
offset: Int
|
|
byteWidth: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
UInt
|
readLong
abstract fun readLong(offset: Int, byteWidth: Int, alignment: Int): Long
Reads a Long from the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
offset: Int
|
|
byteWidth: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Long
|
readULong
abstract fun readULong(offset: Int, byteWidth: Int, alignment: Int): ULong
Parameters
| Name | Description |
|---|---|
offset: Int
|
|
byteWidth: Int
|
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alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
ULong
|
readFloat
abstract fun readFloat(offset: Int, alignment: Int): Float
Reads a Float from the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
offset: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Float
|
readDouble
abstract fun readDouble(offset: Int, alignment: Int): Double
Reads a Double from the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
offset: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Double
|
writeInt
abstract fun writeInt(value: Int, offset: Int, byteWidth: Int, alignment: Int)
Writes an Int to the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
value: Int
|
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offset: Int
|
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byteWidth: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
writeUInt
abstract fun writeUInt(value: UInt, offset: Int, byteWidth: Int, alignment: Int)
Parameters
| Name | Description |
|---|---|
value: UInt
|
|
offset: Int
|
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byteWidth: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
writeLong
abstract fun writeLong(value: Long, offset: Int, byteWidth: Int, alignment: Int)
Writes a Long to the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
value: Long
|
|
offset: Int
|
|
byteWidth: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
writeULong
abstract fun writeULong(value: ULong, offset: Int, byteWidth: Int, alignment: Int)
Parameters
| Name | Description |
|---|---|
value: ULong
|
|
offset: Int
|
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byteWidth: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
writeFloat
abstract fun writeFloat(value: Float, offset: Int, alignment: Int)
Writes a Float to the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
value: Float
|
|
offset: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
writeDouble
abstract fun writeDouble(value: Double, offset: Int, alignment: Int)
Writes a Double to the Memory at the given offset.
Parameters
| Name | Description |
|---|---|
value: Double
|
|
offset: Int
|
|
alignment: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
readBytes
abstract fun readBytes(out: ByteArray, memoryOffset: Int, outOffset: Int, length: Int): Int
Reads length bytes starting at the given memoryOffset from the Memory into the supplied ByteArray, starting at outOffset and returns the number of bytes which were able to be read.
Parameters
| Name | Description |
|---|---|
out: ByteArray
|
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memoryOffset: Int
|
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outOffset: Int
|
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length: Int
|
ReturnValue
| Name | Description |
|---|---|
Int
|
writeBytes
abstract fun writeBytes(value: ByteArray, offset: Int, valueOffset: Int, valueLength: Int)
Writes a ByteArray into the Memory at the given offset.
Optional arguments valueOffset and valueLength allow the caller to specify a subsequence of bytes from the value to write. Defaults for these arguments result in the entirety of the value being written.
Parameters
| Name | Description |
|---|---|
value: ByteArray
|
|
offset: Int
|
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valueOffset: Int
|
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valueLength: Int
|
ReturnValue
| Name | Description |
|---|---|
Unit
|
growBy
abstract fun growBy(newPages: Int): Int
Grows the Memory by the specified number of newPages (each page's size = PAGE_SIZE).
Parameters
| Name | Description |
|---|---|
newPages: Int
|
ReturnValue
| Name | Description |
|---|---|
Int
|
the size of the Memory before the grow operation if the grow was successful, else GROW_FAILURE. |
CompanionObject
Memory
interface Memory
Defines runtime memory for use by a wasm program, along with facilities for accessing and mutating memory by the host JVM application.
From the docs:
A memory instance is the runtime representation of a linear memory. It holds a vector of bytes and an optional maximum size, if one was specified at the definition site of the memory.
meminst ::= {data vec(byte), max u32?}
The length of the vector always is a multiple of the WebAssembly page size, which is defined to
be the constant 65536 – abbreviated 64Ki. Like in a memory type, the maximum size in a memory
instance is given in units of this page size.
The bytes can be mutated through memory instructions, the execution of a data segment, or by external means provided by the embedder.
It is an invariant of the semantics that the length of the byte vector, divided by page size, never exceeds the maximum size, if present.
Fields
| Name | Description |
|---|---|
const PAGE_SIZE: Int
|
|
const GROW_FAILURE: Int
|
Methods
pagesForBytes
fun pagesForBytes(bytes: Long): Int
Returns the minimum number of pages required to hold the specified number of bytes.
Parameters
| Name | Description |
|---|---|
bytes: Long
|
ReturnValue
| Name | Description |
|---|---|
Int
|
Defines runtime memory for use by a wasm program, along with facilities for accessing and mutating memory by the host JVM application.
From the docs:
A memory instance is the runtime representation of a linear memory. It holds a vector of bytes and an optional maximum size, if one was specified at the definition site of the memory.
The length of the vector always is a multiple of the WebAssembly page size, which is defined to be the constant
65536– abbreviated64Ki. Like in a memory type, the maximum size in a memory instance is given in units of this page size.The bytes can be mutated through memory instructions, the execution of a data segment, or by external means provided by the embedder.
It is an invariant of the semantics that the length of the byte vector, divided by page size, never exceeds the maximum size, if present.