gecko-dev/storage/src/mozStorageBindingParams.h

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 * Contributor(s):
 *   Shawn Wilsher <me@shawnwilsher.com> (Original Author)
 *   Andrew Sutherland <asutherland@asutherland.org>
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#ifndef _mozStorageBindingParams_h_
#define _mozStorageBindingParams_h_

#include "nsCOMArray.h"
#include "nsIVariant.h"
#include "nsTHashtable.h"

#include "mozStorageBindingParamsArray.h"
#include "mozStorageStatement.h"
#include "mozStorageAsyncStatement.h"

#include "mozIStorageBindingParams.h"
#include "IStorageBindingParamsInternal.h"

namespace mozilla {
namespace storage {

class BindingParams : public mozIStorageBindingParams
                    , public IStorageBindingParamsInternal
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_MOZISTORAGEBINDINGPARAMS
  NS_DECL_ISTORAGEBINDINGPARAMSINTERNAL

  /**
   * Locks the parameters and prevents further modification to it (such as
   * binding more elements to it).
   */
  void lock();

  /**
   * Unlocks the parameters and allows modification to it again.
   *
   * @param aOwningStatement
   *        The statement that owns us.  We cleared this when we were locked,
   *        and our invariant requires us to have this, so you need to tell us
   *        again.
   */
  void unlock(Statement *aOwningStatement);

  /**
   * @returns the pointer to the owning BindingParamsArray.  Used by a
   *          BindingParamsArray to verify that we belong to it when added.
   */
  const mozIStorageBindingParamsArray *getOwner() const;

  BindingParams(mozIStorageBindingParamsArray *aOwningArray,
                Statement *aOwningStatement);
  virtual ~BindingParams() {}

protected:
  BindingParams(mozIStorageBindingParamsArray *aOwningArray);
  nsCOMArray<nsIVariant> mParameters;
  bool mLocked;

private:

  /**
   * Track the BindingParamsArray that created us until we are added to it.
   * (Once we are added we are locked and no one needs to look up our owner.)
   * Ref-counted since there is no invariant that guarantees it stays alive
   * otherwise.  This keeps mOwningStatement alive for us too since the array
   * also holds a reference.
   */
  nsCOMPtr<mozIStorageBindingParamsArray> mOwningArray;
  /**
   * Used in the synchronous binding case to map parameter names to indices.
   * Not reference-counted because this is only non-null as long as mOwningArray
   * is non-null and mOwningArray also holds a statement reference.
   */
  Statement *mOwningStatement;
  PRUint32 mParamCount;
};

/**
 * Adds late resolution of named parameters so they don't get resolved until we
 * try and bind the parameters on the async thread.  We also stop checking
 * parameter indices for being too big since we just just don't know how many
 * there are.
 *
 * We support *either* binding by name or binding by index.  Trying to do both
 * results in only binding by name at sqlite3_stmt bind time.
 */
class AsyncBindingParams : public BindingParams
{
public:
  NS_SCRIPTABLE NS_IMETHOD BindByName(const nsACString & aName,
                                      nsIVariant *aValue);
  NS_SCRIPTABLE NS_IMETHOD BindByIndex(PRUint32 aIndex, nsIVariant *aValue);

  virtual already_AddRefed<mozIStorageError> bind(sqlite3_stmt * aStatement);

  AsyncBindingParams(mozIStorageBindingParamsArray *aOwningArray);
  virtual ~AsyncBindingParams() {}

private:
  nsInterfaceHashtable<nsCStringHashKey, nsIVariant> mNamedParameters;

  struct NamedParameterIterationClosureThunk
  {
    AsyncBindingParams *self;
    sqlite3_stmt *statement;
    nsCOMPtr<mozIStorageError> err;
  };

  static PLDHashOperator iterateOverNamedParameters(const nsACString &aName,
                                                    nsIVariant *aValue,
                                                    void *voidClosureThunk);
};

} // namespace storage
} // namespace mozilla

#endif // _mozStorageBindingParams_h_