dom/xslt/xslt/txKeyFunctionCall.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include <utility>
   7
   8 #include "mozilla/HashFunctions.h"
   9 #include "nsGkAtoms.h"
  10 #include "nsReadableUtils.h"
  11 #include "txExecutionState.h"
  12 #include "txKey.h"
  13 #include "txNamespaceMap.h"
  14 #include "txSingleNodeContext.h"
  15 #include "txXSLTFunctions.h"
  16 #include "txXSLTPatterns.h"
  17
  18 using namespace mozilla;
  19
  20 /*
  21  * txKeyFunctionCall
  22  * A representation of the XSLT additional function: key()
  23  */
  24
  25 /*
  26  * Creates a new key function call
  27  */
  28 txKeyFunctionCall::txKeyFunctionCall(txNamespaceMap* aMappings)
  29     : mMappings(aMappings) {}
  30
  31 /*
  32  * Evaluates a key() xslt-function call. First argument is name of key
  33  * to use, second argument is value to look up.
  34  * @param aContext the context node for evaluation of this Expr
  35  * @param aCs      the ContextState containing the stack information needed
  36  *                 for evaluation
  37  * @return the result of the evaluation
  38  */
  39 nsresult txKeyFunctionCall::evaluate(txIEvalContext* aContext,
  40                                      txAExprResult** aResult) {
  41   if (!aContext || !requireParams(2, 2, aContext))
  42     return NS_ERROR_XPATH_BAD_ARGUMENT_COUNT;
  43
  44   txExecutionState* es =
  45       static_cast<txExecutionState*>(aContext->getPrivateContext());
  46
  47   nsAutoString keyQName;
  48   nsresult rv = mParams[0]->evaluateToString(aContext, keyQName);
  49   NS_ENSURE_SUCCESS(rv, rv);
  50
  51   txExpandedName keyName;
  52   rv = keyName.init(keyQName, mMappings, false);
  53   NS_ENSURE_SUCCESS(rv, rv);
  54
  55   RefPtr<txAExprResult> exprResult;
  56   rv = mParams[1]->evaluate(aContext, getter_AddRefs(exprResult));
  57   NS_ENSURE_SUCCESS(rv, rv);
  58
  59   txXPathTreeWalker walker(aContext->getContextNode());
  60   walker.moveToRoot();
  61
  62   RefPtr<txNodeSet> res;
  63   txNodeSet* nodeSet;
  64   if (exprResult->getResultType() == txAExprResult::NODESET &&
  65       (nodeSet =
  66            static_cast<txNodeSet*>(static_cast<txAExprResult*>(exprResult)))
  67               ->size() > 1) {
  68     rv = aContext->recycler()->getNodeSet(getter_AddRefs(res));
  69     NS_ENSURE_SUCCESS(rv, rv);
  70
  71     int32_t i;
  72     for (i = 0; i < nodeSet->size(); ++i) {
  73       nsAutoString val;
  74       txXPathNodeUtils::appendNodeValue(nodeSet->get(i), val);
  75
  76       RefPtr<txNodeSet> nodes;
  77       rv = es->getKeyNodes(keyName, walker.getCurrentPosition(), val, i == 0,
  78                            getter_AddRefs(nodes));
  79       NS_ENSURE_SUCCESS(rv, rv);
  80
  81       res->add(*nodes);
  82     }
  83   } else {
  84     nsAutoString val;
  85     exprResult->stringValue(val);
  86     rv = es->getKeyNodes(keyName, walker.getCurrentPosition(), val, true,
  87                          getter_AddRefs(res));
  88     NS_ENSURE_SUCCESS(rv, rv);
  89   }
  90
  91   *aResult = res;
  92   NS_ADDREF(*aResult);
  93
  94   return NS_OK;
  95 }
  96
  97 Expr::ResultType txKeyFunctionCall::getReturnType() { return NODESET_RESULT; }
  98
  99 bool txKeyFunctionCall::isSensitiveTo(ContextSensitivity aContext) {
 100   return (aContext & NODE_CONTEXT) || argsSensitiveTo(aContext);
 101 }
 102
 103 #ifdef TX_TO_STRING
 104 void txKeyFunctionCall::appendName(nsAString& aDest) {
 105   aDest.Append(nsGkAtoms::key->GetUTF16String());
 106 }
 107 #endif
 108
 109 /**
 110  * Hash functions
 111  */
 112
 113 bool txKeyValueHashEntry::KeyEquals(KeyTypePointer aKey) const {
 114   return mKey.mKeyName == aKey->mKeyName &&
 115          mKey.mRootIdentifier == aKey->mRootIdentifier &&
 116          mKey.mKeyValue.Equals(aKey->mKeyValue);
 117 }
 118
 119 PLDHashNumber txKeyValueHashEntry::HashKey(KeyTypePointer aKey) {
 120   const txKeyValueHashKey* key = static_cast<const txKeyValueHashKey*>(aKey);
 121
 122   return AddToHash(HashString(key->mKeyValue), key->mKeyName.mNamespaceID,
 123                    key->mRootIdentifier, key->mKeyName.mLocalName.get());
 124 }
 125
 126 bool txIndexedKeyHashEntry::KeyEquals(KeyTypePointer aKey) const {
 127   return mKey.mKeyName == aKey->mKeyName &&
 128          mKey.mRootIdentifier == aKey->mRootIdentifier;
 129 }
 130
 131 PLDHashNumber txIndexedKeyHashEntry::HashKey(KeyTypePointer aKey) {
 132   const txIndexedKeyHashKey* key =
 133       static_cast<const txIndexedKeyHashKey*>(aKey);
 134   return HashGeneric(key->mKeyName.mNamespaceID, key->mRootIdentifier,
 135                      key->mKeyName.mLocalName.get());
 136 }
 137
 138 /*
 139  * Class managing XSLT-keys
 140  */
 141
 142 nsresult txKeyHash::getKeyNodes(const txExpandedName& aKeyName,
 143                                 const txXPathNode& aRoot,
 144                                 const nsAString& aKeyValue,
 145                                 bool aIndexIfNotFound, txExecutionState& aEs,
 146                                 txNodeSet** aResult) {
 147   *aResult = nullptr;
 148
 149   int32_t identifier = txXPathNodeUtils::getUniqueIdentifier(aRoot);
 150
 151   txKeyValueHashKey valueKey(aKeyName, identifier, aKeyValue);
 152   txKeyValueHashEntry* valueEntry = mKeyValues.GetEntry(valueKey);
 153   if (valueEntry) {
 154     *aResult = valueEntry->mNodeSet;
 155     NS_ADDREF(*aResult);
 156
 157     return NS_OK;
 158   }
 159
 160   // We didn't find a value. This could either mean that that key has no
 161   // nodes with that value or that the key hasn't been indexed using this
 162   // document.
 163
 164   if (!aIndexIfNotFound) {
 165     // If aIndexIfNotFound is set then the caller knows this key is
 166     // indexed, so don't bother investigating.
 167     *aResult = mEmptyNodeSet;
 168     NS_ADDREF(*aResult);
 169
 170     return NS_OK;
 171   }
 172
 173   txIndexedKeyHashKey indexKey(aKeyName, identifier);
 174   txIndexedKeyHashEntry* indexEntry = mIndexedKeys.PutEntry(indexKey);
 175   NS_ENSURE_TRUE(indexEntry, NS_ERROR_OUT_OF_MEMORY);
 176
 177   if (indexEntry->mIndexed) {
 178     // The key was indexed and apparently didn't contain this value so
 179     // return the empty nodeset.
 180     *aResult = mEmptyNodeSet;
 181     NS_ADDREF(*aResult);
 182
 183     return NS_OK;
 184   }
 185
 186   // The key needs to be indexed.
 187   txXSLKey* xslKey = mKeys.get(aKeyName);
 188   if (!xslKey) {
 189     // The key didn't exist, so bail.
 190     return NS_ERROR_INVALID_ARG;
 191   }
 192
 193   nsresult rv = xslKey->indexSubtreeRoot(aRoot, mKeyValues, aEs);
 194   NS_ENSURE_SUCCESS(rv, rv);
 195
 196   indexEntry->mIndexed = true;
 197
 198   // Now that the key is indexed we can get its value.
 199   valueEntry = mKeyValues.GetEntry(valueKey);
 200   if (valueEntry) {
 201     *aResult = valueEntry->mNodeSet;
 202     NS_ADDREF(*aResult);
 203   } else {
 204     *aResult = mEmptyNodeSet;
 205     NS_ADDREF(*aResult);
 206   }
 207
 208   return NS_OK;
 209 }
 210
 211 nsresult txKeyHash::init() {
 212   mEmptyNodeSet = new txNodeSet(nullptr);
 213
 214   return NS_OK;
 215 }
 216
 217 /**
 218  * Adds a match/use pair.
 219  * @param aMatch  match-pattern
 220  * @param aUse    use-expression
 221  * @return false if an error occurred, true otherwise
 222  */
 223 bool txXSLKey::addKey(UniquePtr<txPattern>&& aMatch, UniquePtr<Expr>&& aUse) {
 224   if (!aMatch || !aUse) return false;
 225
 226   Key* key = mKeys.AppendElement();
 227   if (!key) return false;
 228
 229   key->matchPattern = std::move(aMatch);
 230   key->useExpr = std::move(aUse);
 231
 232   return true;
 233 }
 234
 235 /**
 236  * Indexes a document and adds it to the hash of key values
 237  * @param aRoot         Subtree root to index and add
 238  * @param aKeyValueHash Hash to add values to
 239  * @param aEs           txExecutionState to use for XPath evaluation
 240  */
 241 nsresult txXSLKey::indexSubtreeRoot(const txXPathNode& aRoot,
 242                                     txKeyValueHash& aKeyValueHash,
 243                                     txExecutionState& aEs) {
 244   txKeyValueHashKey key(mName, txXPathNodeUtils::getUniqueIdentifier(aRoot),
 245                         u""_ns);
 246   return indexTree(aRoot, key, aKeyValueHash, aEs);
 247 }
 248
 249 /**
 250  * Recursively searches a node, its attributes and its subtree for
 251  * nodes matching any of the keys match-patterns.
 252  * @param aNode         Node to search
 253  * @param aKey          Key to use when adding into the hash
 254  * @param aKeyValueHash Hash to add values to
 255  * @param aEs           txExecutionState to use for XPath evaluation
 256  */
 257 nsresult txXSLKey::indexTree(const txXPathNode& aNode, txKeyValueHashKey& aKey,
 258                              txKeyValueHash& aKeyValueHash,
 259                              txExecutionState& aEs) {
 260   nsresult rv = testNode(aNode, aKey, aKeyValueHash, aEs);
 261   NS_ENSURE_SUCCESS(rv, rv);
 262
 263   // check if the node's attributes match
 264   txXPathTreeWalker walker(aNode);
 265   if (walker.moveToFirstAttribute()) {
 266     do {
 267       rv = testNode(walker.getCurrentPosition(), aKey, aKeyValueHash, aEs);
 268       NS_ENSURE_SUCCESS(rv, rv);
 269     } while (walker.moveToNextAttribute());
 270     walker.moveToParent();
 271   }
 272
 273   // check if the node's descendants match
 274   if (walker.moveToFirstChild()) {
 275     do {
 276       rv = indexTree(walker.getCurrentPosition(), aKey, aKeyValueHash, aEs);
 277       NS_ENSURE_SUCCESS(rv, rv);
 278     } while (walker.moveToNextSibling());
 279   }
 280
 281   return NS_OK;
 282 }
 283
 284 /**
 285  * Tests one node if it matches any of the keys match-patterns. If
 286  * the node matches its values are added to the index.
 287  * @param aNode         Node to test
 288  * @param aKey          Key to use when adding into the hash
 289  * @param aKeyValueHash Hash to add values to
 290  * @param aEs           txExecutionState to use for XPath evaluation
 291  */
 292 nsresult txXSLKey::testNode(const txXPathNode& aNode, txKeyValueHashKey& aKey,
 293                             txKeyValueHash& aKeyValueHash,
 294                             txExecutionState& aEs) {
 295   nsAutoString val;
 296   uint32_t currKey, numKeys = mKeys.Length();
 297   for (currKey = 0; currKey < numKeys; ++currKey) {
 298     bool matched;
 299     nsresult rv = mKeys[currKey].matchPattern->matches(aNode, &aEs, matched);
 300     NS_ENSURE_SUCCESS(rv, rv);
 301
 302     if (matched) {
 303       aEs.pushEvalContext(new txSingleNodeContext(aNode, &aEs));
 304
 305       RefPtr<txAExprResult> exprResult;
 306       nsresult rv = mKeys[currKey].useExpr->evaluate(
 307           aEs.getEvalContext(), getter_AddRefs(exprResult));
 308
 309       delete aEs.popEvalContext();
 310       NS_ENSURE_SUCCESS(rv, rv);
 311
 312       if (exprResult->getResultType() == txAExprResult::NODESET) {
 313         txNodeSet* res =
 314             static_cast<txNodeSet*>(static_cast<txAExprResult*>(exprResult));
 315         int32_t i;
 316         for (i = 0; i < res->size(); ++i) {
 317           val.Truncate();
 318           txXPathNodeUtils::appendNodeValue(res->get(i), val);
 319
 320           aKey.mKeyValue.Assign(val);
 321           txKeyValueHashEntry* entry = aKeyValueHash.PutEntry(aKey);
 322           NS_ENSURE_TRUE(entry && entry->mNodeSet, NS_ERROR_OUT_OF_MEMORY);
 323
 324           if (entry->mNodeSet->isEmpty() ||
 325               entry->mNodeSet->get(entry->mNodeSet->size() - 1) != aNode) {
 326             entry->mNodeSet->append(aNode);
 327           }
 328         }
 329       } else {
 330         exprResult->stringValue(val);
 331
 332         aKey.mKeyValue.Assign(val);
 333         txKeyValueHashEntry* entry = aKeyValueHash.PutEntry(aKey);
 334         NS_ENSURE_TRUE(entry && entry->mNodeSet, NS_ERROR_OUT_OF_MEMORY);
 335
 336         if (entry->mNodeSet->isEmpty() ||
 337             entry->mNodeSet->get(entry->mNodeSet->size() - 1) != aNode) {
 338           entry->mNodeSet->append(aNode);
 339         }
 340       }
 341     }
 342   }
 343
 344   return NS_OK;
 345 }