--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Services for byte streams and arrays
+module bytes
+
+import kernel
+import collection::array
+intrude import string
+
+# A buffer containing Byte-manipulation facilities
+#
+# Uses Copy-On-Write when persisted
+#
+# TODO: Change the bound to Byte when available in stdlib and bootstrap
+class Bytes
+ super AbstractArray[Int]
+
+ # A NativeString being a char*, it can be used as underlying representation here.
+ private var items: NativeString
+
+ # Number of bytes in the array
+ redef var length: Int
+
+ # Capacity of the array
+ private var capacity: Int
+
+ # Has this buffer been persisted (to_s'd)?
+ #
+ # Used for Copy-On-Write
+ private var persisted = false
+
+ # var b = new Bytes.empty
+ # assert b.to_s == ""
+ init empty do
+ var ns = new NativeString(0)
+ init(ns, 0, 0)
+ end
+
+ init with_capacity(cap: Int) do
+ var ns = new NativeString(cap)
+ init(ns, 0, cap)
+ end
+
+ redef fun is_empty do return length != 0
+
+ # var b = new Bytes.empty
+ # b.add 101
+ # assert b[0] == 101
+ redef fun [](i: Int): Int do
+ assert i >= 0
+ assert i < length
+ return items[i].ascii
+ end
+
+ # var b = new Bytes.with_capacity(1)
+ # b[0] = 101
+ # assert b.to_s == "e"
+ redef fun []=(i: Int, v: Int) do
+ if persisted then regen
+ assert i >= 0
+ assert i <= length
+ if i == length then add(v)
+ items[i] = v.ascii
+ end
+
+ # var b = new Bytes.empty
+ # b.add 101
+ # assert b.to_s == "e"
+ redef fun add(c: Int) do
+ if persisted then regen
+ if length >= capacity then
+ enlarge(length)
+ end
+ items[length] = c.ascii
+ length += 1
+ end
+
+ # var b = new Bytes.empty
+ # b.append([104, 101, 108, 108, 111])
+ # assert b.to_s == "hello"
+ redef fun append(arr: Collection[Int]) do
+ if arr isa Bytes then
+ append_ns(arr.items, arr.length)
+ else
+ for i in arr do add i
+ end
+ end
+
+ redef fun clear do length = 0
+
+ # Regenerates the buffer, necessary when it was persisted
+ private fun regen do
+ var nns = new NativeString(capacity)
+ items.copy_to(nns, length, 0, 0)
+ persisted = false
+ end
+
+ # Appends the `ln` first bytes of `ns` to self
+ fun append_ns(ns: NativeString, ln: Int) do
+ if persisted then regen
+ var nlen = length + ln
+ if nlen > capacity then enlarge(nlen)
+ ns.copy_to(items, ln, 0, length)
+ length += ln
+ end
+
+ # Appends `ln` bytes from `ns` starting at index `from` to self
+ fun append_ns_from(ns: NativeString, ln, from: Int) do
+ if persisted then regen
+ var nlen = length + ln
+ if nlen > capacity then enlarge(nlen)
+ ns.copy_to(items, ln, from, length)
+ length += ln
+ end
+
+ redef fun enlarge(sz) do
+ if capacity >= sz then return
+ persisted = false
+ while capacity < sz do capacity = capacity * 2 + 2
+ var ns = new NativeString(capacity)
+ items.copy_to(ns, length, 0, 0)
+ items = ns
+ end
+
+ redef fun to_s do
+ persisted = true
+ return new FlatString.with_infos(items, length, 0, length -1)
+ end
+
+ redef fun iterator do return new BytesIterator.with_buffer(self)
+end
+
+private class BytesIterator
+ super IndexedIterator[Int]
+
+ var tgt: NativeString
+
+ redef var index: Int
+
+ var max: Int
+
+ init with_buffer(b: Bytes) do init(b.items, 0, b.length - 1)
+
+ redef fun is_ok do return index < max
+
+ redef fun next do index += 1
+
+ redef fun item do return tgt[index].ascii
+end
+
+redef class NativeString
+ fun to_bytes: Bytes do
+ var len = cstring_length
+ return new Bytes(self, len, len)
+ end
+end
nitlanguage / nit.git / commitdiff