1886 if (isInvalid()) {
1887 return 0L;
1888 }
1889 return fs.getSpace(this, FileSystem.SPACE_USABLE);
1890 }
1891
1892 /* -- Temporary files -- */
1893
1894 private static class TempDirectory {
1895 private TempDirectory() { }
1896
1897 // temporary directory location
1898 private static final File tmpdir = new File(
1899 GetPropertyAction.privilegedGetProperty("java.io.tmpdir"));
1900 static File location() {
1901 return tmpdir;
1902 }
1903
1904 // file name generation
1905 private static final SecureRandom random = new SecureRandom();
1906 static File generateFile(String prefix, String suffix, File dir)
1907 throws IOException
1908 {
1909 long n = random.nextLong();
1910
1911 // Use only the file name from the supplied prefix
1912 prefix = (new File(prefix)).getName();
1913 String name = prefix + Long.toUnsignedString(n) + suffix;
1914 File f = new File(dir, name);
1915 if (!name.equals(f.getName()) || f.isInvalid()) {
1916 if (System.getSecurityManager() != null)
1917 throw new IOException("Unable to create temporary file");
1918 else
1919 throw new IOException("Unable to create temporary file, " + f);
1920 }
1921 return f;
1922 }
1923 }
1924
1925 /**
1926 * <p> Creates a new empty file in the specified directory, using the
1927 * given prefix and suffix strings to generate its name. If this method
1928 * returns successfully then it is guaranteed that:
1929 *
1930 * <ol>
1931 * <li> The file denoted by the returned abstract pathname did not exist
1932 * before this method was invoked, and
1933 * <li> Neither this method nor any of its variants will return the same
1934 * abstract pathname again in the current invocation of the virtual
1935 * machine.
1936 * </ol>
1937 *
1938 * This method provides only part of a temporary-file facility. To arrange
1939 * for a file created by this method to be deleted automatically, use the
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1886 if (isInvalid()) {
1887 return 0L;
1888 }
1889 return fs.getSpace(this, FileSystem.SPACE_USABLE);
1890 }
1891
1892 /* -- Temporary files -- */
1893
1894 private static class TempDirectory {
1895 private TempDirectory() { }
1896
1897 // temporary directory location
1898 private static final File tmpdir = new File(
1899 GetPropertyAction.privilegedGetProperty("java.io.tmpdir"));
1900 static File location() {
1901 return tmpdir;
1902 }
1903
1904 // file name generation
1905 private static final SecureRandom random = new SecureRandom();
1906 private static String shortenSubName(String subName, int excess,
1907 int nameMin) {
1908 long newLength = Math.max(nameMin, subName.length() - excess);
1909 if (newLength < subName.length()) {
1910 subName = subName.substring(0, (int)newLength);
1911 }
1912 return subName;
1913 }
1914 static File generateFile(String prefix, String suffix, File dir)
1915 throws IOException
1916 {
1917 long n = random.nextLong();
1918 String nus = Long.toUnsignedString(n);
1919
1920 // Use only the file name from the supplied prefix
1921 prefix = (new File(prefix)).getName();
1922 String name = prefix + nus + suffix;
1923
1924 // Shorten the name if it exceeds the maximum path component length
1925 long nameMax = fs.getNameMax(dir.getPath());
1926 int excess = name.length() - (int)nameMax;
1927 if (excess > 0) {
1928 // Attempt to shorten the prefix length to no less then 3
1929 prefix = shortenSubName(prefix, excess, 3);
1930 name = prefix + nus + suffix;
1931 excess = name.length() - (int)nameMax;
1932 }
1933 if (excess > 0) {
1934 // Attempt to shorten the suffix length to no less than
1935 // 0 or 4 depending on whether it begins with a dot ('.')
1936 suffix = shortenSubName(suffix, excess,
1937 suffix.indexOf(".") == 0 ? 4 : 0);
1938 name = prefix + nus + suffix;
1939 excess = name.length() - (int)nameMax;
1940 }
1941 if (excess > 0 && excess <= nus.length() - 5) {
1942 // Attempt to shorten the random string length to no less than 5
1943 nus = shortenSubName(nus, excess, 5);
1944 name = prefix + nus + suffix;
1945 }
1946
1947 File f = new File(dir, name);
1948 if (!name.equals(f.getName()) || f.isInvalid()) {
1949 if (System.getSecurityManager() != null)
1950 throw new IOException("Unable to create temporary file");
1951 else
1952 throw new IOException("Unable to create temporary file, "
1953 + f);
1954 }
1955 return f;
1956 }
1957 }
1958
1959 /**
1960 * <p> Creates a new empty file in the specified directory, using the
1961 * given prefix and suffix strings to generate its name. If this method
1962 * returns successfully then it is guaranteed that:
1963 *
1964 * <ol>
1965 * <li> The file denoted by the returned abstract pathname did not exist
1966 * before this method was invoked, and
1967 * <li> Neither this method nor any of its variants will return the same
1968 * abstract pathname again in the current invocation of the virtual
1969 * machine.
1970 * </ol>
1971 *
1972 * This method provides only part of a temporary-file facility. To arrange
1973 * for a file created by this method to be deleted automatically, use the
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