1 files changed, 55 insertions, 0 deletions
diff --git a/okio/src/jsMain/kotlin/okio/FileSource.kt b/okio/src/jsMain/kotlin/okio/FileSource.kt
new file mode 100644
index 00000000..1b4f496f
--- /dev/null
+++ b/okio/src/jsMain/kotlin/okio/FileSource.kt
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2020 Square, Inc.
+ *
+ * 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.
+ */
+package okio
+
+import org.khronos.webgl.Uint8Array
+import org.khronos.webgl.get
+
+internal class FileSource(
+  private val fd: Number
+) : Source {
+  var closed = false
+
+  override fun read(sink: Buffer, byteCount: Long): Long {
+    require(byteCount >= 0L) { "byteCount < 0: $byteCount" }
+    check(!closed) { "closed" }
+
+    val data = Uint8Array(byteCount.toInt())
+    val readByteCount = readSync(
+      fd = fd,
+      buffer = data,
+      length = byteCount,
+      offset = 0,
+      position = null
+    ).toInt()
+
+    if (readByteCount == 0) return -1L
+
+    for (i in 0 until readByteCount) {
+      sink.writeByte(data[i].toInt())
+    }
+
+    return readByteCount.toLong()
+  }
+
+  override fun timeout(): Timeout = Timeout.NONE
+
+  override fun close() {
+    if (closed) return
+    closed = true
+    closeSync(fd)
+  }
+}