1 files changed, 105 insertions, 0 deletions
diff --git a/lib/src/main/kotlin/QID.kt b/lib/src/main/kotlin/QID.kt
new file mode 100644
index 0000000..4d0bd6a
--- /dev/null
+++ b/lib/src/main/kotlin/QID.kt
@@ -0,0 +1,105 @@
+import net.InMessage
+import net.OutMessage
+import java.math.BigInteger
+
+/**
+ * This class holds information about a single QID.
+ */
+class QID {
+    /**
+     * Does the QID represent a directory?
+     */
+    val isDirectory get() = getIsDirectory()
+
+    /**
+     * Does the QID represent an append-only file?
+     */
+    val isAppendOnly get() = getIsAppendOnly()
+
+    /**
+     * Does the QID represent an exclusive-use file?
+     */
+    val isExclusive get() = getIsExclusive()
+
+    /**
+     * Does the QID represent a temporary file?
+     */
+    val isTemporary get() = getIsTemporary()
+
+    /**
+     * The QID type.
+     */
+    val type: UByte
+
+    /**
+     * The QID file version.
+     */
+    val version: UInt
+
+    /**
+     * The QID path.
+     */
+    val path: ULong
+
+    /**
+     * Constructor for a QID with separate fields. See the `stat(5)` manual page for more information about [type],
+     * [version], and [path].
+     *
+     * @param type The QID type.
+     * @param version The QID file version.
+     * @param path The QID path.
+     */
+    constructor(type: UByte, version: UInt, path: ULong) {
+        this.type = type
+        this.version = version
+        this.path = path
+    }
+
+    /**
+     * Constructor for raw QID data. Only the first 13 elements are read.
+     *
+     * @param raw The raw QID data.
+     * @throws IllegalArgumentException if [raw] does not have at least 13 elements.
+     */
+    constructor(raw: List<UByte>) {
+        require(raw.size >= 13)
+        this.type = raw.first()
+        val rawVersion = raw.slice(1..4)
+        val rawPath = raw.slice(5..12)
+        this.version = InMessage.convInteger(rawVersion, 0, rawVersion.size).toInt().toUInt()
+        this.path = InMessage.convInteger(rawPath, 0, rawPath.size).toLong().toULong()
+    }
+
+    /**
+     * Check bit values in [type]. In case of multiple bits, the method returns true if at least one of them is 1.
+     *
+     * @param bits A byte whose bits set to 1 are checked.
+     */
+    private fun checkTypeBits(bits: UByte): Boolean {
+        return this.type.and(bits) != 0u.toUByte()
+    }
+
+    private fun getIsDirectory(): Boolean {
+        return checkTypeBits(0x80u)
+    }
+
+    private fun getIsAppendOnly(): Boolean {
+        return checkTypeBits(0x40u)
+    }
+
+    private fun getIsExclusive(): Boolean {
+        return checkTypeBits(0x20u)
+    }
+
+    private fun getIsTemporary(): Boolean {
+        return checkTypeBits(0x04u)
+    }
+
+    fun toRaw(): List<UByte> {
+        var bytes: List<UByte> = emptyList()
+        bytes += this.type
+        bytes += OutMessage.convIntegerToBytes(BigInteger(this.version.toString()), 4u)
+        bytes += OutMessage.convIntegerToBytes(BigInteger(this.path.toString()), 8u)
+        return bytes
+    }
+}
+\ No newline at end of file