summaryrefslogtreecommitdiff
path: root/src/reflect/scala/reflect/io/AbstractFile.scala
blob: bcefcc471ff76cb955f8fa7e17deed9c315ad3d1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author  Martin Odersky
 */


package scala
package reflect
package io

import java.io.{ FileOutputStream, IOException, InputStream, OutputStream, BufferedOutputStream, ByteArrayOutputStream }
import java.io.{ File => JFile }
import java.net.URL
import scala.collection.mutable.ArrayBuffer
import scala.reflect.internal.util.Statistics

/**
 * An abstraction over files for use in the reflection/compiler libraries.
 *
 * ''Note:  This library is considered experimental and should not be used unless you know what you are doing.''
 *
 * @author Philippe Altherr
 * @version 1.0, 23/03/2004
 */
object AbstractFile {
  /** Returns "getFile(new File(path))". */
  def getFile(path: String): AbstractFile = getFile(File(path))
  def getFile(path: Path): AbstractFile = getFile(path.toFile)

  /**
   * If the specified File exists and is a regular file, returns an
   * abstract regular file backed by it. Otherwise, returns `null`.
   */
  def getFile(file: File): AbstractFile =
    if (file.isFile) new PlainFile(file) else null

  /** Returns "getDirectory(new File(path))". */
  def getDirectory(path: Path): AbstractFile = getDirectory(path.toFile)

  /**
   * If the specified File exists and is either a directory or a
   * readable zip or jar archive, returns an abstract directory
   * backed by it. Otherwise, returns `null`.
   */
  def getDirectory(file: File): AbstractFile =
    if (file.isDirectory) new PlainFile(file)
    else if (file.isFile && Path.isExtensionJarOrZip(file.jfile)) ZipArchive fromFile file
    else null

  /**
   * If the specified URL exists and is a regular file or a directory, returns an
   * abstract regular file or an abstract directory, respectively, backed by it.
   * Otherwise, returns `null`.
   */
  def getURL(url: URL): AbstractFile =
    if (url.getProtocol == "file") {
      val f = new java.io.File(url.getPath)
      if (f.isDirectory) getDirectory(f)
      else getFile(f)
    } else null

  def getResources(url: URL): AbstractFile = ZipArchive fromManifestURL url
}

/**
 * <p>
 *   This class and its children serve to unify handling of files and
 *   directories. These files and directories may or may not have some
 *   real counter part within the file system. For example, some file
 *   handles reference files within a zip archive or virtual ones
 *   that exist only in memory.
 * </p>
 * <p>
 *   Every abstract file has a path (i.e. a full name) and a name
 *   (i.e. a short name) and may be backed by some real File. There are
 *   two different kinds of abstract files: regular files and
 *   directories. Regular files may be read and have a last modification
 *   time. Directories may list their content and look for subfiles with
 *   a specified name or path and of a specified kind.
 * </p>
 * <p>
 *   The interface does <b>not</b> allow to access the content.
 *   The class `symtab.classfile.AbstractFileReader` accesses
 *   bytes, knowing that the character set of classfiles is UTF-8. For
 *   all other cases, the class `SourceFile` is used, which honors
 *   `global.settings.encoding.value`.
 * </p>
 *
 * ''Note:  This library is considered experimental and should not be used unless you know what you are doing.''
 */
abstract class AbstractFile extends Iterable[AbstractFile] {

  /** Returns the name of this abstract file. */
  def name: String

  /** Returns the path of this abstract file. */
  def path: String

  /** Returns the path of this abstract file in a canonical form. */
  def canonicalPath: String = if (file == null) path else file.getCanonicalPath

  /** Checks extension case insensitively. */
  def hasExtension(other: String) = extension == other.toLowerCase
  private lazy val extension: String = Path.extension(name)

  /** The absolute file, if this is a relative file. */
  def absolute: AbstractFile

  /** Returns the containing directory of this abstract file */
  def container : AbstractFile

  /** Returns the underlying File if any and null otherwise. */
  def file: JFile

  /** An underlying source, if known.  Mostly, a zip/jar file. */
  def underlyingSource: Option[AbstractFile] = None

  /** Does this abstract file denote an existing file? */
  def exists: Boolean = {
    if (Statistics.canEnable) Statistics.incCounter(IOStats.fileExistsCount)
    (file eq null) || file.exists
  }

  /** Does this abstract file represent something which can contain classfiles? */
  def isClassContainer = isDirectory || (file != null && (extension == "jar" || extension == "zip"))

  /** Create a file on disk, if one does not exist already. */
  def create(): Unit

  /** Delete the underlying file or directory (recursively). */
  def delete(): Unit

  /** Is this abstract file a directory? */
  def isDirectory: Boolean

  /** Does this abstract file correspond to something on-disk? */
  def isVirtual: Boolean = false

  /** Returns the time that this abstract file was last modified. */
  def lastModified: Long

  /** returns an input stream so the file can be read */
  def input: InputStream

  /** Returns an output stream for writing the file */
  def output: OutputStream

  /** Returns a buffered output stream for writing the file - defaults to out */
  def bufferedOutput: BufferedOutputStream = new BufferedOutputStream(output)

  /** size of this file if it is a concrete file. */
  def sizeOption: Option[Int] = None

  def toURL: URL = if (file == null) null else file.toURI.toURL

  /** Returns contents of file (if applicable) in a Char array.
   *  warning: use `Global.getSourceFile()` to use the proper
   *  encoding when converting to the char array.
   */
  @throws(classOf[IOException])
  def toCharArray = new String(toByteArray).toCharArray

  /** Returns contents of file (if applicable) in a byte array.
   */
  @throws(classOf[IOException])
  def toByteArray: Array[Byte] = {
    val in = input
    sizeOption match {
      case Some(size) =>
        var rest = size
        val arr = new Array[Byte](rest)
        while (rest > 0) {
          val res = in.read(arr, arr.length - rest, rest)
          if (res == -1)
            throw new IOException("read error")
          rest -= res
        }
        in.close()
        arr
      case None =>
        val out = new ByteArrayOutputStream()
        var c = in.read()
        while(c != -1) {
          out.write(c)
          c = in.read()
        }
        in.close()
        out.toByteArray()
    }
  }

  /** Returns all abstract subfiles of this abstract directory. */
  def iterator: Iterator[AbstractFile]

  /** Returns the abstract file in this abstract directory with the specified
   *  name. If there is no such file, returns `null`. The argument
   *  `directory` tells whether to look for a directory or
   *  a regular file.
   */
  def lookupName(name: String, directory: Boolean): AbstractFile

  /** Returns an abstract file with the given name. It does not
   *  check that it exists.
   */
  def lookupNameUnchecked(name: String, directory: Boolean): AbstractFile

  /** Return an abstract file that does not check that `path` denotes
   *  an existing file.
   */
  def lookupPathUnchecked(path: String, directory: Boolean): AbstractFile = {
    lookup((f, p, dir) => f.lookupNameUnchecked(p, dir), path, directory)
  }

  private def lookup(getFile: (AbstractFile, String, Boolean) => AbstractFile,
                     path0: String,
                     directory: Boolean): AbstractFile = {
    val separator = java.io.File.separatorChar
    // trim trailing '/'s
    val path: String = if (path0.last == separator) path0 dropRight 1 else path0
    val length = path.length()
    assert(length > 0 && !(path.last == separator), path)
    var file = this
    var start = 0
    while (true) {
      val index = path.indexOf(separator, start)
      assert(index < 0 || start < index, ((path, directory, start, index)))
      val name = path.substring(start, if (index < 0) length else index)
      file = getFile(file, name, if (index < 0) directory else true)
      if ((file eq null) || index < 0) return file
      start = index + 1
    }
    file
  }

  private def fileOrSubdirectoryNamed(name: String, isDir: Boolean): AbstractFile = {
    val lookup = lookupName(name, isDir)
    if (lookup != null) lookup
    else {
      val jfile = new JFile(file, name)
      if (isDir) jfile.mkdirs() else jfile.createNewFile()
      new PlainFile(jfile)
    }
  }

  /**
   * Get the file in this directory with the given name,
   * creating an empty file if it does not already existing.
   */
  def fileNamed(name: String): AbstractFile = {
    assert(isDirectory, "Tried to find '%s' in '%s' but it is not a directory".format(name, path))
    fileOrSubdirectoryNamed(name, isDir = false)
  }

  /**
   * Get the subdirectory with a given name, creating it if it
   * does not already exist.
   */
  def subdirectoryNamed(name: String): AbstractFile = {
    assert (isDirectory, "Tried to find '%s' in '%s' but it is not a directory".format(name, path))
    fileOrSubdirectoryNamed(name, isDir = true)
  }

  protected def unsupported(): Nothing = unsupported(null)
  protected def unsupported(msg: String): Nothing = throw new UnsupportedOperationException(msg)

  /** Returns the path of this abstract file. */
  override def toString() = path

}