public void Dispose()
{
_revWalk.Dispose();
COMPLETE.Dispose();
IN_WORK_QUEUE.Dispose();
LOCALLY_SEEN.Dispose();
_objectDigest.Dispose();
}
/// <summary>
/// Produces a hash for the paths of adjacent bnodes for a bnode,
/// incorporating all information about its subgraph of bnodes.
/// </summary>
/// <remarks>
/// Produces a hash for the paths of adjacent bnodes for a bnode,
/// incorporating all information about its subgraph of bnodes. This method
/// will recursively pick adjacent bnode permutations that produce the
/// lexicographically-least 'path' serializations.
/// </remarks>
/// <param name="id">the ID of the bnode to hash paths for.</param>
/// <param name="bnodes">the map of bnode quads.</param>
/// <param name="namer">the canonical bnode namer.</param>
/// <param name="pathNamer">the namer used to assign names to adjacent bnodes.</param>
/// <param name="callback">(err, result) called once the operation completes.</param>
private static NormalizeUtils.HashResult HashPaths(string id, IDictionary <string, IDictionary <string, object> > bnodes, UniqueNamer namer, UniqueNamer pathNamer)
{
#if !PORTABLE
MessageDigest md = null;
try
{
// create SHA-1 digest
md = MessageDigest.GetInstance("SHA-1");
JObject groups = new JObject();
IList <string> groupHashes;
IList <RDFDataset.Quad> quads = (IList <RDFDataset.Quad>)bnodes[id]["quads"];
for (int hpi = 0; ; hpi++)
{
if (hpi == quads.Count)
{
// done , hash groups
groupHashes = new List <string>(groups.GetKeys());
((List <string>)groupHashes).Sort(StringComparer.CurrentCultureIgnoreCase);
for (int hgi = 0; ; hgi++)
{
if (hgi == groupHashes.Count)
{
NormalizeUtils.HashResult res = new NormalizeUtils.HashResult();
res.hash = EncodeHex(md.Digest());
res.pathNamer = pathNamer;
return(res);
}
// digest group hash
string groupHash = groupHashes[hgi];
md.Update(JsonLD.JavaCompat.GetBytesForString(groupHash, "UTF-8"));
// choose a path and namer from the permutations
string chosenPath = null;
UniqueNamer chosenNamer = null;
NormalizeUtils.Permutator permutator = new NormalizeUtils.Permutator((JArray)groups[groupHash]);
while (true)
{
bool contPermutation = false;
bool breakOut = false;
JArray permutation = permutator.Next();
UniqueNamer pathNamerCopy = pathNamer.Clone();
// build adjacent path
string path = string.Empty;
JArray recurse = new JArray();
foreach (string bnode in permutation)
{
// use canonical name if available
if (namer.IsNamed(bnode))
{
path += namer.GetName(bnode);
}
else
{
// recurse if bnode isn't named in the path
// yet
if (!pathNamerCopy.IsNamed(bnode))
{
recurse.Add(bnode);
}
path += pathNamerCopy.GetName(bnode);
}
// skip permutation if path is already >= chosen
// path
if (chosenPath != null && path.Length >= chosenPath.Length && string.CompareOrdinal
(path, chosenPath) > 0)
{
// return nextPermutation(true);
if (permutator.HasNext())
{
contPermutation = true;
}
else
{
// digest chosen path and update namer
md.Update(JsonLD.JavaCompat.GetBytesForString(chosenPath, "UTF-8"));
pathNamer = chosenNamer;
// hash the nextGroup
breakOut = true;
}
break;
}
}
// if we should do the next permutation
if (contPermutation)
{
continue;
}
// if we should stop processing this group
if (breakOut)
{
break;
}
// does the next recursion
for (int nrn = 0; ; nrn++)
{
if (nrn == recurse.Count)
{
// return nextPermutation(false);
if (chosenPath == null || string.CompareOrdinal(path, chosenPath) < 0)
{
chosenPath = path;
chosenNamer = pathNamerCopy;
}
if (!permutator.HasNext())
{
// digest chosen path and update namer
md.Update(JsonLD.JavaCompat.GetBytesForString(chosenPath, "UTF-8"));
pathNamer = chosenNamer;
// hash the nextGroup
breakOut = true;
}
break;
}
// do recursion
string bnode_1 = (string)recurse[nrn];
NormalizeUtils.HashResult result = HashPaths(bnode_1, bnodes, namer, pathNamerCopy);
path += pathNamerCopy.GetName(bnode_1) + "<" + result.hash + ">";
pathNamerCopy = result.pathNamer;
// skip permutation if path is already >= chosen
// path
if (chosenPath != null && path.Length >= chosenPath.Length && string.CompareOrdinal
(path, chosenPath) > 0)
{
// return nextPermutation(true);
if (!permutator.HasNext())
{
// digest chosen path and update namer
md.Update(JsonLD.JavaCompat.GetBytesForString(chosenPath, "UTF-8"));
pathNamer = chosenNamer;
// hash the nextGroup
breakOut = true;
}
break;
}
}
// do next recursion
// if we should stop processing this group
if (breakOut)
{
break;
}
}
}
}
// get adjacent bnode
IDictionary <string, object> quad = (IDictionary <string, object>)quads[hpi];
string bnode_2 = GetAdjacentBlankNodeName((IDictionary <string, object>)quad["subject"
], id);
string direction = null;
if (bnode_2 != null)
{
// normal property
direction = "p";
}
else
{
bnode_2 = GetAdjacentBlankNodeName((IDictionary <string, object>)quad["object"], id
);
if (bnode_2 != null)
{
// reverse property
direction = "r";
}
}
if (bnode_2 != null)
{
// get bnode name (try canonical, path, then hash)
string name;
if (namer.IsNamed(bnode_2))
{
name = namer.GetName(bnode_2);
}
else
{
if (pathNamer.IsNamed(bnode_2))
{
name = pathNamer.GetName(bnode_2);
}
else
{
name = HashQuads(bnode_2, bnodes, namer);
}
}
// hash direction, property, end bnode name/hash
using (MessageDigest md1 = MessageDigest.GetInstance("SHA-1"))
{
// String toHash = direction + (String) ((Map<String,
// Object>) quad.get("predicate")).get("value") + name;
md1.Update(JsonLD.JavaCompat.GetBytesForString(direction, "UTF-8"));
md1.Update(JsonLD.JavaCompat.GetBytesForString(((string)((IDictionary <string, object>)quad["predicate"])["value"]), "UTF-8"));
md1.Update(JsonLD.JavaCompat.GetBytesForString(name, "UTF-8"));
string groupHash = EncodeHex(md1.Digest());
if (groups.ContainsKey(groupHash))
{
((JArray)groups[groupHash]).Add(bnode_2);
}
else
{
JArray tmp = new JArray();
tmp.Add(bnode_2);
groups[groupHash] = tmp;
}
}
}
}
}
catch
{
// TODO: i don't expect that SHA-1 is even NOT going to be
// available?
// look into this further
throw;
}
finally
{
md?.Dispose();
}
#else
throw new PlatformNotSupportedException();
#endif
}
