/// <exception cref="System.IO.IOException"/>
private string SchemeFromPath(Path path)
{
string scheme = path.ToUri().GetScheme();
if (scheme == null)
{
if (fs != null)
{
scheme = fs.GetUri().GetScheme();
}
else
{
scheme = fc.GetFSofPath(fc.FixRelativePart(path)).GetUri().GetScheme();
}
}
return(scheme);
}
/// <summary>
/// Performs the operation specified by the next function, calling it
/// repeatedly until all symlinks in the given path are resolved.
/// </summary>
/// <param name="fc">FileContext used to access file systems.</param>
/// <param name="path">The path to resolve symlinks on.</param>
/// <returns>Generic type determined by the implementation of next.</returns>
/// <exception cref="System.IO.IOException"/>
public virtual T Resolve(FileContext fc, Path path)
{
int count = 0;
T @in = null;
Path p = path;
// NB: More than one AbstractFileSystem can match a scheme, eg
// "file" resolves to LocalFs but could have come by RawLocalFs.
AbstractFileSystem fs = fc.GetFSofPath(p);
// Loop until all symlinks are resolved or the limit is reached
for (bool isLink = true; isLink;)
{
try
{
@in = Next(fs, p);
isLink = false;
}
catch (UnresolvedLinkException e)
{
if (!fc.resolveSymlinks)
{
throw new IOException("Path " + path + " contains a symlink" + " and symlink resolution is disabled ("
+ CommonConfigurationKeys.FsClientResolveRemoteSymlinksKey + ").", e);
}
if (!FileSystem.AreSymlinksEnabled())
{
throw new IOException("Symlink resolution is disabled in" + " this version of Hadoop."
);
}
if (count++ > FsConstants.MaxPathLinks)
{
throw new IOException("Possible cyclic loop while " + "following symbolic link "
+ path);
}
// Resolve the first unresolved path component
p = QualifySymlinkTarget(fs.GetUri(), p, fs.GetLinkTarget(p));
fs = fc.GetFSofPath(p);
}
}
return(@in);
}
