gecko-dev/dom/src/base/nsScriptNameSpaceManager.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * The Original Code is Mozilla Communicator client code.
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#include "nsScriptNameSpaceManager.h"
#include "nsCOMPtr.h"
#include "nsIComponentManager.h"
#include "nsICategoryManager.h"
#include "nsIServiceManager.h"
#include "nsISupportsPrimitives.h"
#include "nsIScriptExternalNameSet.h"
#include "nsIScriptNameSpaceManager.h"
#include "nsIScriptContext.h"
#include "nsIInterfaceInfoManager.h"
#include "nsIInterfaceInfo.h"
#include "xptinfo.h"
#include "nsXPIDLString.h"
#include "nsReadableUtils.h"


#define NS_DOM_INTERFACE_PREFIX "nsIDOM"

// Our extended PLDHashEntryHdr
class GlobalNameMapEntry : public PLDHashEntryHdr
{
public:
  // Our hash table ops don't care about the order of these members
  nsString mKey;
  nsGlobalNameStruct mGlobalName;
};


PR_STATIC_CALLBACK(const void *)
GlobalNameHashGetKey(PLDHashTable *table, PLDHashEntryHdr *entry)
{
  GlobalNameMapEntry *e = NS_STATIC_CAST(GlobalNameMapEntry *, entry);

  return NS_STATIC_CAST(const nsAString *, &e->mKey);
}

PR_STATIC_CALLBACK(PLDHashNumber)
GlobalNameHashHashKey(PLDHashTable *table, const void *key)
{
  const nsAString *str = NS_STATIC_CAST(const nsAString *, key);

  return HashString(*str);
}

PR_STATIC_CALLBACK(PRBool)
GlobalNameHashMatchEntry(PLDHashTable *table, const PLDHashEntryHdr *entry,
                         const void *key)
{
  const GlobalNameMapEntry *e =
    NS_STATIC_CAST(const GlobalNameMapEntry *, entry);
  const nsAString *str = NS_STATIC_CAST(const nsAString *, key);

  return str->Equals(e->mKey);
}

PR_STATIC_CALLBACK(void)
GlobalNameHashClearEntry(PLDHashTable *table, PLDHashEntryHdr *entry)
{
  GlobalNameMapEntry *e = NS_STATIC_CAST(GlobalNameMapEntry *, entry);

  // An entry is being cleared, let the key (nsString) do its own
  // cleanup.
  e->mKey.~nsString();

  // This will set e->mGlobalName.mType to
  // nsGlobalNameStruct::eTypeNotInitialized
  memset(&e->mGlobalName, 0, sizeof(nsGlobalNameStruct));
}

PR_STATIC_CALLBACK(void)
GlobalNameHashInitEntry(PLDHashTable *table, PLDHashEntryHdr *entry,
                        const void *key)
{
  GlobalNameMapEntry *e = NS_STATIC_CAST(GlobalNameMapEntry *, entry);
  const nsAString *keyStr = NS_STATIC_CAST(const nsAString *, key);

  // Inititlize the key in the entry with placement new
  nsString *str = new (&e->mKey) nsString(*keyStr);

  // This will set e->mGlobalName.mType to
  // nsGlobalNameStruct::eTypeNotInitialized
  memset(&e->mGlobalName, 0, sizeof(nsGlobalNameStruct));
}

nsScriptNameSpaceManager::nsScriptNameSpaceManager()
  : mIsInitialized(PR_FALSE)
{
}

nsScriptNameSpaceManager::~nsScriptNameSpaceManager()
{
  if (mIsInitialized) {
    // Destroy the hash
    PL_DHashTableFinish(&mGlobalNames);
  }
}

nsGlobalNameStruct *
nsScriptNameSpaceManager::AddToHash(const nsAString& aKey)
{
  GlobalNameMapEntry *entry =
    NS_STATIC_CAST(GlobalNameMapEntry *,
                   PL_DHashTableOperate(&mGlobalNames, &aKey, PL_DHASH_ADD));

  if (!entry) {
    return nsnull;
  }

  return &entry->mGlobalName;
}

nsresult
nsScriptNameSpaceManager::FillHash(nsICategoryManager *aCategoryManager,
                                   const char *aCategory,
                                   nsGlobalNameStruct::nametype aType)
{
  nsCOMPtr<nsISimpleEnumerator> e;
  nsresult rv = aCategoryManager->EnumerateCategory(aCategory,
                                                    getter_AddRefs(e));
  NS_ENSURE_SUCCESS(rv, rv);

  nsXPIDLCString categoryEntry;
  nsXPIDLCString contractId;
  nsCOMPtr<nsISupports> entry;

  while (NS_SUCCEEDED(e->GetNext(getter_AddRefs(entry)))) {
    nsCOMPtr<nsISupportsString> category(do_QueryInterface(entry));

    if (!category) {
      NS_WARNING("Category entry not an nsISupportsString!");

      continue;
    }

    rv = category->GetData(getter_Copies(categoryEntry));

    aCategoryManager->GetCategoryEntry(aCategory, categoryEntry,
                                       getter_Copies(contractId));
    NS_ENSURE_SUCCESS(rv, rv);

    nsCID cid;

    rv = nsComponentManager::ContractIDToClassID(contractId, &cid);

    if (NS_FAILED(rv)) {
      NS_WARNING("Bad contract id registed with the script namespace manager");

      // Make sure we don't leak this error code to the caller.
      rv = NS_OK;

      continue;
    }

    nsGlobalNameStruct *s = AddToHash(NS_ConvertASCIItoUCS2(categoryEntry));
    NS_ENSURE_TRUE(s, NS_ERROR_OUT_OF_MEMORY);

    if (s->mType == nsGlobalNameStruct::eTypeNotInitialized) {
      s->mType = aType;
      s->mCID = cid;
    } else {
      NS_WARNING("Global script name not overwritten!");
    }
  }

  return rv;
}


// This method enumerates over all installed interfaces (in .xpt
// files) and finds ones that start with "nsIDOM" and has constants
// defined in the interface itself (inherited constants doesn't
// count), once such an interface is found the "nsIDOM" prefix is cut
// off the name and the rest of the name is added into the hash for
// global names. This makes things like 'Node.ELEMENT_NODE' work in
// JS. See nsWindowSH::GlobalResolve() for detais on how this is used.

nsresult
nsScriptNameSpaceManager::FillHashWithDOMInterfaces()
{
  nsCOMPtr<nsIInterfaceInfoManager> iim =
    dont_AddRef(XPTI_GetInterfaceInfoManager());
  NS_ENSURE_TRUE(iim, NS_ERROR_UNEXPECTED);

  nsCOMPtr<nsIEnumerator> e;
  nsresult rv =
    iim->EnumerateInterfacesWhoseNamesStartWith(NS_DOM_INTERFACE_PREFIX,
                                                getter_AddRefs(e));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsISupports> entry;

  rv = e->First();

  if (NS_FAILED(rv)) {
    // Empty interface list?

    NS_WARNING("What, no nsIDOM interfaces installed?");

    return NS_OK;
  }

  for ( ; e->IsDone() == NS_COMFALSE; e->Next()) {
    rv = e->CurrentItem(getter_AddRefs(entry));
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIInterfaceInfo> if_info(do_QueryInterface(entry));

    NS_ASSERTION(if_info, "Interface info not an nsIInterfaceInfo!");

    // With the InterfaceInfo system it is actually cheaper to get the 
    // interface name than to get the count of constants. The former is 
    // always cached. The latter might require loading an xpt file!

    nsXPIDLCString if_name;

    rv = if_info->GetName(getter_Copies(if_name));
    NS_ENSURE_SUCCESS(rv, rv);

    PRUint16 constant_count = 0;

    rv = if_info->GetConstantCount(&constant_count);
    if (NS_FAILED(rv)) {
      NS_ERROR("can't get constant count");
      continue;
    }

    if (constant_count) {
      PRUint16 parent_constant_count = 0;

      nsCOMPtr<nsIInterfaceInfo> parent_info;

      if_info->GetParent(getter_AddRefs(parent_info));

      if (parent_info) {
        rv = parent_info->GetConstantCount(&parent_constant_count);
        if (NS_FAILED(rv)) {
          NS_ERROR("can't get constant count");
          continue;
        }
      }

      if (constant_count != parent_constant_count) {
        nsGlobalNameStruct *s =
          AddToHash(NS_ConvertASCIItoUCS2(if_name.get() +
                                          strlen(NS_DOM_INTERFACE_PREFIX)));
        NS_ENSURE_TRUE(s, NS_ERROR_OUT_OF_MEMORY);

#ifdef DEBUG
        NS_ASSERTION(s->mType == nsGlobalNameStruct::eTypeNotInitialized,
                     "Whaaa, interface name already in hash!");
#endif

        s->mType = nsGlobalNameStruct::eTypeInterface;
      }
    }
  }

  return rv;
}

nsresult
nsScriptNameSpaceManager::Init()
{
  static PLDHashTableOps hash_table_ops =
  {
    PL_DHashAllocTable,
    PL_DHashFreeTable,
    GlobalNameHashGetKey,
    GlobalNameHashHashKey,
    GlobalNameHashMatchEntry,
    PL_DHashMoveEntryStub,
    GlobalNameHashClearEntry,
    PL_DHashFinalizeStub,
    GlobalNameHashInitEntry
  };

  mIsInitialized = PL_DHashTableInit(&mGlobalNames, &hash_table_ops, nsnull,
                                     sizeof(GlobalNameMapEntry), 128);
  NS_ENSURE_TRUE(mIsInitialized, NS_ERROR_OUT_OF_MEMORY);

  nsresult rv = NS_OK;

  rv = FillHashWithDOMInterfaces();
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsICategoryManager> cm =
    do_GetService(NS_CATEGORYMANAGER_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = FillHash(cm, JAVASCRIPT_GLOBAL_CONSTRUCTOR_CATEGORY,
                nsGlobalNameStruct::eTypeExternalConstructor);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = FillHash(cm, JAVASCRIPT_GLOBAL_PROPERTY_CATEGORY,
                nsGlobalNameStruct::eTypeProperty);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = FillHash(cm, JAVASCRIPT_GLOBAL_STATIC_NAMESET_CATEGORY,
                nsGlobalNameStruct::eTypeStaticNameSet);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = FillHash(cm, JAVASCRIPT_GLOBAL_DYNAMIC_NAMESET_CATEGORY,
                nsGlobalNameStruct::eTypeDynamicNameSet);
  NS_ENSURE_SUCCESS(rv, rv);

  return NS_OK;
}

PR_STATIC_CALLBACK(PLDHashOperator)
NameSetInitCallback(PLDHashTable *table, PLDHashEntryHdr *hdr,
                    PRUint32 number, void *arg)
{
  GlobalNameMapEntry *entry = NS_STATIC_CAST(GlobalNameMapEntry *, hdr);

  if (entry->mGlobalName.mType == nsGlobalNameStruct::eTypeStaticNameSet) {
    nsresult rv = NS_OK;
    nsCOMPtr<nsIScriptExternalNameSet> ns =
      do_CreateInstance(entry->mGlobalName.mCID, &rv);
    NS_ENSURE_SUCCESS(rv, PL_DHASH_NEXT);

    rv = ns->InitializeNameSet(NS_STATIC_CAST(nsIScriptContext *, arg));
    NS_WARN_IF_FALSE(NS_SUCCEEDED(rv),
                     "Initing external script classes failed!");
  }

  return PL_DHASH_NEXT;
}

nsresult
nsScriptNameSpaceManager::InitForContext(nsIScriptContext *aContext)
{
  PL_DHashTableEnumerate(&mGlobalNames, NameSetInitCallback, aContext);

  return NS_OK;
}

nsresult
nsScriptNameSpaceManager::LookupName(const nsAString& aName,
                                     const nsGlobalNameStruct **aNameStruct)
{
  GlobalNameMapEntry *entry =
    NS_STATIC_CAST(GlobalNameMapEntry *,
                   PL_DHashTableOperate(&mGlobalNames, &aName,
                                        PL_DHASH_LOOKUP));

  if (PL_DHASH_ENTRY_IS_BUSY(entry)) {
    *aNameStruct = &entry->mGlobalName;
  } else {
    *aNameStruct = nsnull;
  }

  return NS_OK;
}

nsresult
nsScriptNameSpaceManager::RegisterClassName(const char *aClassName,
                                            PRInt32 aDOMClassInfoID)
{
  nsGlobalNameStruct *s = AddToHash(NS_ConvertASCIItoUCS2(aClassName));
  NS_ENSURE_TRUE(s, NS_ERROR_OUT_OF_MEMORY);

  if (s) {
    if (s->mType == nsGlobalNameStruct::eTypeClassConstructor) {
      return NS_OK;
    }

    // If a external constructor is already defined with aClassName we
    // won't overwrite it.

    if (s->mType == nsGlobalNameStruct::eTypeExternalConstructor) {
      return NS_OK;
    }
  }

  NS_ASSERTION(!(s && s->mType != nsGlobalNameStruct::eTypeInterface),
               "Whaaa, JS environment name clash!");

  s->mType = nsGlobalNameStruct::eTypeClassConstructor;
  s->mDOMClassInfoID = aDOMClassInfoID;

  return NS_OK;
}

nsresult
nsScriptNameSpaceManager::RegisterClassProto(const char *aClassName,
                                             const nsIID *aConstructorProtoIID,
                                             PRBool *aFoundOld)
{
  NS_ENSURE_ARG_POINTER(aConstructorProtoIID);

  *aFoundOld = PR_FALSE;

  nsGlobalNameStruct *s = AddToHash(NS_ConvertASCIItoUCS2(aClassName));
  NS_ENSURE_TRUE(s, NS_ERROR_OUT_OF_MEMORY);

  if (s->mType != nsGlobalNameStruct::eTypeNotInitialized &&
      s->mType != nsGlobalNameStruct::eTypeInterface) {
    *aFoundOld = PR_TRUE;

    return NS_OK;
  }

  s->mType = nsGlobalNameStruct::eTypeClassProto;
  s->mIID = *aConstructorProtoIID;

  return NS_OK;
}