Merge pull request #6 from XYOracleNetwork/develop

Updates for XyoBuff

src/main/java/network/xyo/sdkobjectmodelkotlin/XyoCache.kt

@@ -0,0 +1,52 @@
+package network.xyo.sdkobjectmodelkotlin
+
+import java.lang.ref.WeakReference
+
+/**
+ * A simple caching file that used weak references to cache any item.
+ *
+ * @type T Is the type of the object wishing to cache, this also but me the type of the XyoCacheAble interface.
+ * @property itemToCache The XyoCacheAble interface to get a FRESH item, to cache.
+ */
+class XyoCache<T> (private val itemToCache : XyoCacheAble<T>) {
+    private var reference : WeakReference<T>? = null
+
+    /**
+     * The cache-able interface to cache any item.
+     *
+     * @type iT The type that the get get function returns. (The type of the item to cache)
+     */
+    interface XyoCacheAble<iT> {
+
+        /**
+         * Gets a clean instance of the object.
+         *
+         * @return iT The clean (not cached) item.
+         */
+        fun get() : iT
+    }
+
+    /**
+     * Gets the item from the cache, if not in the cache it item will be collected freshly and cached.
+     *
+     * @return The cached or clean item of type T.
+     */
+    fun get () : T {
+        val cachedItem = reference?.get()
+
+        if (cachedItem != null) {
+            return cachedItem
+        }
+
+        val newItem = itemToCache.get()
+        reference = WeakReference(newItem)
+        return newItem
+    }
+
+    /**
+     * Clears the cache, the next time the this.get() function is called, the cache will be updated.
+     */
+    fun clear () {
+        reference = null
+    }
+}

src/main/java/network/xyo/sdkobjectmodelkotlin/buffer/XyoBuff.kt

@@ -0,0 +1,130 @@
+package network.xyo.sdkobjectmodelkotlin.buffer
+
+import network.xyo.sdkobjectmodelkotlin.exceptions.XyoObjectException
+import network.xyo.sdkobjectmodelkotlin.objects.XyoNumberEncoder
+import network.xyo.sdkobjectmodelkotlin.objects.toHexString
+import network.xyo.sdkobjectmodelkotlin.schema.XyoObjectSchema
+import java.nio.*
+
+/**
+ * A base class for <i>XyoObjects</i>. This is used for obtaining the schema, value, and size of the item.
+ */
+abstract class XyoBuff {
+    /**
+     * The primary data input for the XyoBuff. This buffer will not be read before the allowedOffset.
+     */
+    protected abstract var item : ByteArray
+
+    /**
+     * The sizes of the headers to read. This should align with XyoObjectSchema. This value should be set to 0 when
+     * dealing with typed elements in a typed array.
+     */
+    protected open val headerSize : Int = 2
+
+    /**
+     * The starting offset of where to read. This buffer will not be read past this buffer.
+     */
+    abstract val allowedOffset : Int
+
+    /**
+     * The XyoObjectSchema of the XyoBuff
+     */
+    open val schema : XyoObjectSchema
+        get() {
+            return  XyoObjectSchema.createFromHeader(item.copyOfRange(allowedOffset, allowedOffset + headerSize))
+        }
+
+    /**
+     * The size of the object, in bytes.
+     *
+     * NOTE: This does not include the first two header bytes.
+     */
+    open val sizeBytes : Int
+        get() {
+            return readSizeOfObject(schema.sizeIdentifier, allowedOffset + headerSize)
+        }
+
+    /**
+     * The value of the object. The value of the object is the object without the size, or the 2 byte header.
+     */
+    open val valueCopy : ByteArray
+        get() {
+            return item.copyOfRange(
+                    headerSize + schema.sizeIdentifier + allowedOffset,
+                    headerSize + allowedOffset + sizeBytes
+            )
+        }
+
+    /**
+     * All of the bytes for the object including the header and size.
+     */
+    open val bytesCopy : ByteArray
+        get() {
+            return item.copyOfRange(allowedOffset, allowedOffset + sizeBytes + headerSize)
+        }
+
+
+    /**
+     * Reads the size of the object at a current index.
+     *
+     * @param sizeToReadForSize The number of bytes to read for the size.
+     * @param offset The offset at which to read the size.
+     * @throws XyoObjectException Ig the sizeToReadForSize is not [1, 2, 4]
+     */
+    protected fun readSizeOfObject (sizeToReadForSize : Int, offset: Int) : Int {
+        val buffer = ByteBuffer.allocate(sizeToReadForSize)
+        buffer.put(item.copyOfRange(offset, offset + sizeToReadForSize))
+
+        when (sizeToReadForSize) {
+            1 -> return buffer[0].toInt() and 0xFF
+            2 -> return buffer.getShort(0).toInt() and 0xFFFF
+            4 -> return buffer.getInt(0)
+        }
+
+        throw XyoObjectException("Stub for long count. Value: ${item.toHexString()}")
+    }
+
+    companion object {
+        /**
+         * Creates a XyoBuff with a schema and a value.
+         *
+         * @param schema The schema to create the object with.
+         * @param value The value of the object to encode. This does NOT include size.
+         */
+        fun newInstance (schema : XyoObjectSchema, value : ByteArray) : XyoBuff {
+            return object : XyoBuff() {
+                override val schema: XyoObjectSchema = schema
+                override var item: ByteArray = getObjectEncoded(schema, value)
+                override val valueCopy: ByteArray = value
+                override val allowedOffset: Int = 0
+            }
+        }
+
+        /**
+         * Wraps a given XyoBuff in byte form and creates a XyoBuff.
+         *
+         * @param buff The encoded XyoBuffer, this value can be obtained from myBuff.bytesCopy
+         * @return The represented XyoBuff.
+         */
+        fun wrap (buff : ByteArray) : XyoBuff {
+            return object : XyoBuff() {
+                override val allowedOffset: Int = 0
+                override var item: ByteArray = buff
+            }
+        }
+
+        /**
+         * Encodes a XyoBuff given a value and schema.
+         *
+         * @param schema The schema of the XyoBuff to create.
+         * @param value The value of the XyoBuff to create. This does NOT include size.
+         */
+        fun getObjectEncoded (schema: XyoObjectSchema, value: ByteArray) : ByteArray {
+            val buffer = ByteBuffer.allocate(value.size + schema.sizeIdentifier + 2)
+            buffer.put(schema.header)
+            buffer.put(XyoNumberEncoder.createSize(value.size, schema.sizeIdentifier))
+            buffer.put(value)
+            return buffer.array()
+        }
+    }
+}

src/main/java/network/xyo/sdkobjectmodelkotlin/exceptions/XyoObjectException.kt

@@ -0,0 +1,10 @@
+package network.xyo.sdkobjectmodelkotlin.exceptions
+
+import java.lang.Exception
+
+/**
+ * A base exception for all all XyoObject related items (all internal functions).
+ *
+ * @property message The message of the exception.
+ */
+open class XyoObjectException (override val message: String?) : Exception()

src/main/java/network/xyo/sdkobjectmodelkotlin/exceptions/XyoObjectIteratorException.kt

@@ -2,5 +2,7 @@ package network.xyo.sdkobjectmodelkotlin.exceptions
 
 /**
  * An exception thrown when using an XyoObjectIterator.
+ *
+ * @property message The message of the exception.
  */
-class XyoObjectIteratorException (message: String?) : XyoObjectExceotion(message)
+class XyoObjectIteratorException (message: String?) : XyoObjectException(message)

src/main/java/network/xyo/sdkobjectmodelkotlin/exceptions/XyoSchemaException.kt

@@ -2,5 +2,7 @@ package network.xyo.sdkobjectmodelkotlin.exceptions
 
 /**
  * An exception for schema relates issues.
+ *
+ * @property message The message of the exception.
  */
-class XyoSchemaException(message: String?) : XyoObjectExceotion(message)
+class XyoSchemaException(message: String?) : XyoObjectException(message)

src/main/java/network/xyo/sdkobjectmodelkotlin/objects/XyoByteArrayToHexString.kt

@@ -0,0 +1,21 @@
+package network.xyo.sdkobjectmodelkotlin.objects
+
+import java.lang.StringBuilder
+
+/**
+ * A function to encode ByteArrays into strings.
+ *
+ * [0x13, 0x37] -> 0x1337
+ *
+ * @return A string in base 16 (hex) of the ByteArray. All uppercase.
+ */
+fun ByteArray.toHexString(): String {
+    val builder = StringBuilder()
+    val it = this.iterator()
+    builder.append("0x")
+    while (it.hasNext()) {
+        builder.append(String.format("%02X", it.next()))
+    }
+
+    return builder.toString()
+}