1 /*
2 * Copyright 2017 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package trebuchet.io
18
19 import kotlin.sequences.iterator
20
findNewlineInWindownull21 private fun findNewlineInWindow(window: StreamingReader.Window, startIndex: Long): Long {
22 for (i in startIndex..window.globalEndIndex) {
23 if (window[i] == '\n'.toByte()) return i
24 }
25 return -1
26 }
27
28 /**
29 * Iterates over all the lines in the stream, skipping any empty line. Lines do not contain
30 * the line-end marker(s). Handles both LF & CRLF endings.
31 */
<lambda>null32 fun StreamingReader.iterLines() = iterator {
33 val stream = this@iterLines
34
35 var lineStartIndex = stream.startIndex
36 while (true) {
37 var index = lineStartIndex
38 var foundAt = -1L
39 while (true) {
40 if (index > stream.endIndex) {
41 if (!stream.loadIndex(index)) break
42 }
43 val window = stream.windowFor(index)
44 foundAt = findNewlineInWindow(window, index)
45 if (foundAt != -1L) break
46 index = window.globalEndIndex + 1
47 }
48
49 // Reached EOF with no data, return
50 if (lineStartIndex > stream.endIndex) break
51
52 // Reached EOF, consume remaining as a line
53 if (foundAt == -1L) foundAt = stream.endIndex + 1
54
55 val nextStart = foundAt + 1
56
57 // Handle CLRF
58 if (foundAt > 0 && stream[foundAt - 1] == '\r'.toByte()) foundAt -= 1
59
60 val lineEndIndexInclusive = foundAt - 1
61 if (lineStartIndex >= stream.startIndex && (lineEndIndexInclusive - lineStartIndex) >= 0) {
62 val window = stream.windowFor(lineStartIndex)
63 if (window === stream.windowFor(lineEndIndexInclusive)) {
64 // slice endIndex is exclusive
65 yield(window.slice.slice((lineStartIndex - window.globalStartIndex).toInt(),
66 (lineEndIndexInclusive - window.globalStartIndex + 1).toInt()))
67 } else {
68 val tmpBuffer = ByteArray((lineEndIndexInclusive - lineStartIndex + 1).toInt())
69 stream.copyTo(tmpBuffer, lineStartIndex, lineEndIndexInclusive)
70 yield(tmpBuffer.asSlice())
71 }
72 }
73 lineStartIndex = nextStart
74 }
75 }
76