added io_stream.wrap_bytearray

res/modules/internal/stream_providers/bytearray.lua

@@ -0,0 +1,126 @@
+local io_stream = require "core:io_stream"
+
+local lib = { }
+
+local buffers = { }
+local positions = { }
+
+local nextDescriptor = 0
+
+local function openDescriptor(buffer)
+    nextDescriptor = nextDescriptor + 1
+
+    buffers[nextDescriptor] = buffer
+    positions[nextDescriptor] = 1
+
+    return nextDescriptor
+end
+
+local function requireDescriptor(descriptor)
+    if not buffers[descriptor] then
+        error("unknown descriptor")
+    end
+end
+
+function lib.read(descriptor, length)
+    requireDescriptor(descriptor)
+
+    local buf = buffers[descriptor]
+    local bufLength = #buf
+    local pos = positions[descriptor]
+
+    local toRead = math.min(bufLength - pos + 1, length)
+
+    if toRead <= 0 then
+        return Bytearray()
+    end
+
+    local segment = buf:slice(pos, toRead)
+
+    positions[descriptor] = pos + toRead
+
+    return segment
+end
+
+function lib.write(descriptor, data)
+    requireDescriptor(descriptor)
+
+    local buf = buffers[descriptor]
+    local pos = positions[descriptor]
+
+    local bufLength = #buf
+    local dataLength = #data
+
+    local endPos = pos + dataLength - 1
+
+    -- size ensuring
+    if endPos > bufLength then
+        for i = bufLength + 1, endPos do
+            buf[i] = 0
+        end
+    end
+
+    for i = 1, dataLength do
+        buf[i + pos - 1] = data[i]
+    end
+
+    positions[descriptor] = pos + dataLength
+end
+
+function lib.seek(descriptor, mode, offset)
+    requireDescriptor(descriptor)
+
+    local buf = buffers[descriptor]
+    local bufLength = #buf
+
+    local base
+
+    if mode == 'b' then
+        base = 1
+    elseif mode == 'c' then
+        base = positions[descriptor]
+    elseif mode == 'e' then
+        base = bufLength + 1
+    else error('invalid seek mode') end
+
+    local newPos = base + offset
+
+    if newPos < 1 then
+        error('failed to seek stream')
+    end
+
+    positions[descriptor] = newPos
+end
+
+function lib.tell(descriptor)
+    requireDescriptor(descriptor)
+
+    return positions[descriptor]
+end
+
+function lib.flush(descriptor)
+    requireDescriptor(descriptor)
+end
+
+function lib.is_alive(descriptor)
+    return buffers[descriptor] ~= nil
+end
+
+function lib.close(descriptor)
+    requireDescriptor(descriptor)
+
+    buffers[descriptor] = nil
+    positions[descriptor] = nil
+end
+
+return function(buffer, binaryMode)
+    if binaryMode == nil then
+        binaryMode = true
+    end
+
+    return io_stream.new(
+        openDescriptor(buffer),
+        binaryMode,
+        lib
+    )
+end

res/scripts/stdlib.lua

@@ -332,6 +332,8 @@ else
     os.pid = ffi.C.getpid()
 end
 
+require("core:io_stream").wrap_bytearray = require "core:internal/stream_providers/bytearray"
+
 math.randomseed(time.uptime() * 1536227939)
 
 rules = require "core:internal/rules"