1 files changed, 118 insertions, 0 deletions
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/PickleBuffer.scala b/src/compiler/scala/tools/nsc/symtab/classfile/PickleBuffer.scala
new file mode 100644
index 0000000000..aed16bf057
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/PickleBuffer.scala
@@ -0,0 +1,118 @@
+/* NSC -- new scala compiler
+ * Copyright 2005 LAMP/EPFL
+ * @author  Martin Odersky
+ */
+// $Id$
+package scala.tools.nsc.symtab.classfile;
+
+/** Variable length byte arrays, with methods for basic pickling and unpickling.
+ *  @param data: The initial buffer
+ *  @param from: The first index where defined data are found
+ *  @param to  : The first index where new data can be written
+ */
+class PickleBuffer(data: Array[byte], from: int, to: int) {
+
+  var bytes = data;
+  var readIndex = from;
+  var writeIndex = to;
+
+  /** Double bytes array */
+  private def dble: unit = {
+    val bytes1 = new Array[byte](bytes.length * 2);
+    System.arraycopy(bytes, 0, bytes1, 0, writeIndex);
+    bytes = bytes1
+  }
+
+  def ensureCapacity(capacity: int) = while (bytes.length < writeIndex + capacity) dble;
+
+  // -- Basic output routines --------------------------------------------
+
+  /** Write a byte of data */
+  def writeByte(b: int): unit = {
+    if (writeIndex == bytes.length) dble;
+    bytes(writeIndex) = b.asInstanceOf[byte];
+    writeIndex = writeIndex + 1
+  }
+
+  /** Write a natural number in big endian format, base 128.
+   *  All but the last digits have bit 0x80 set.*/
+  def writeNat(x: int): unit = {
+    def writeNatPrefix(x: int): unit = {
+      val y = x >>> 7;
+      if (y != 0) writeNatPrefix(y);
+      writeByte((x & 0x7f) | 0x80);
+    }
+    val y = x >>> 7;
+    if (y != 0) writeNatPrefix(y);
+    writeByte(x & 0x7f)
+  }
+
+  /** Write a natural number at `pos'
+   *  If number is more than one byte, shift rest of array to make space. */
+  def patchNat(pos: int, x: int): unit = {
+    def patchNatPrefix(x: int): unit = {
+      writeByte(0);
+      System.arraycopy(bytes, pos, bytes, pos+1, writeIndex - (pos+1));
+      bytes(pos) = ((x & 0x7f) | 0x80).asInstanceOf[byte];
+      val y = x >>> 7;
+      if (y != 0) patchNatPrefix(y)
+    }
+    bytes(pos) = (x & 0x7f).asInstanceOf[byte];
+    val y = x >>> 7;
+    if (y != 0) patchNatPrefix(y);
+  }
+
+  /** Write a long number in signed big endian format, base 256. */
+  def writeLong(x: long): unit = {
+    val y = x >> 8;
+    val z = x & 0xff;
+    if (-y != (z >> 7)) writeLong(y);
+    writeByte(z.asInstanceOf[int]);
+  }
+
+  // -- Basic input routines --------------------------------------------
+
+  /** Read a byte */
+  def readByte(): int = {
+    val x = bytes(readIndex); readIndex = readIndex + 1; x
+  }
+
+  /** Read a natural number in big endian format, base 128.
+   *  All but the last digits have bit 0x80 set.*/
+  def readNat(): int = {
+    var b = 0;
+    var x = 0;
+    do {
+      b = readByte();
+      x = (x << 7) + (b & 0x7f);
+    } while ((b & 0x80) != 0);
+    x
+  }
+
+  /** Read a long number in signed big endian format, base 256. */
+  def readLong(len: int): long = {
+    var x = 0L;
+    var i = 0;
+    while (i < len) {
+      x = (x << 8) + (readByte() & 0xff);
+      i = i + 1
+    }
+    val leading = 64 - (len << 3);
+    x << leading >> leading
+  }
+
+  /** Perform operation `op' until readIndex == end. Concatenate results into a list. */
+  def until[T](end: int, op: () => T): List[T] =
+    if (readIndex == end) List() else op() :: until(end, op);
+
+  /** Create an index */
+  def createIndex: Array[int] = {
+    val index = new Array[int](readNat());
+    for (val i <- Iterator.range(0, index.length)) {
+      index(i) = readIndex;
+      readByte();
+      readIndex = readNat() + readIndex
+    }
+    index
+  }
+}