StorageBaseStatementInternal.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=2 sts=2 expandtab
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_storage_StorageBaseStatementInternal_h_
#define mozilla_storage_StorageBaseStatementInternal_h_

#include "nsISupports.h"
#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "mozStorageHelper.h"

struct sqlite3;
struct sqlite3_stmt;
class mozIStorageBindingParamsArray;
class mozIStorageBindingParams;
class mozIStorageStatementCallback;
class mozIStoragePendingStatement;

namespace mozilla {
namespace storage {

#define STORAGEBASESTATEMENTINTERNAL_IID             \
  {                                                  \
    0xd18856c9, 0xbf07, 0x4ae2, {                    \
      0x94, 0x5b, 0x1a, 0xdd, 0x49, 0x19, 0x55, 0x2a \
    }                                                \
  }

class Connection;
class StatementData;

class AsyncStatementFinalizer;

/**
 * Implementation-only interface and shared logix mix-in corresponding to
 * mozIStorageBaseStatement.  Both Statement and AsyncStatement inherit from
 * this. The interface aspect makes them look the same to implementation innards
 * that aren't publicly accessible.  The mix-in avoids code duplication in
 * common implementations of mozIStorageBaseStatement, albeit with some minor
 * performance/space overhead because we have to use defines to officially
 * implement the methods on Statement/AsyncStatement (and proxy to this base
 * class.)
 */
class StorageBaseStatementInternal : public nsISupports {
 public:
  NS_DECLARE_STATIC_IID_ACCESSOR(STORAGEBASESTATEMENTINTERNAL_IID)

  /**
   * @return the connection that this statement belongs to.
   */
  Connection *getOwner() { return mDBConnection; }

  /**
   * Return the asynchronous statement, creating it if required.
   *
   * This is for use by the asynchronous execution code for StatementData
   * created by AsyncStatements.  Statement internally uses this method to
   * prepopulate StatementData with the sqlite3_stmt.
   *
   * @param[out] stmt
   *             The sqlite3_stmt for asynchronous use.
   * @return The SQLite result code for creating the statement if created,
   *         SQLITE_OK if creation was not required.
   */
  virtual int getAsyncStatement(sqlite3_stmt **_stmt) = 0;

  /**
   * Obtains the StatementData needed for asynchronous execution.
   *
   * This is for use by Connection to retrieve StatementData from statements
   * when executeAsync is invoked.
   *
   * @param[out] _data
   *             A reference to a StatementData object that will be populated
   *             upon successful execution of this method.
   * @return NS_OK if we were able to assemble the data, failure otherwise.
   */
  virtual nsresult getAsynchronousStatementData(StatementData &_data) = 0;

  /**
   * Construct a new BindingParams to be owned by the provided binding params
   * array.  This method exists so that BindingParamsArray does not need
   * factory logic to determine what type of BindingParams to instantiate.
   *
   * @param aOwner
   *        The binding params array to own the newly created binding params.
   * @return The new mozIStorageBindingParams instance appropriate to the
   *         underlying statement type.
   */
  virtual already_AddRefed<mozIStorageBindingParams> newBindingParams(
      mozIStorageBindingParamsArray *aOwner) = 0;

 protected:  // mix-in bits are protected
  StorageBaseStatementInternal();

  RefPtr<Connection> mDBConnection;
  sqlite3 *mNativeConnection;

  /**
   * Our asynchronous statement.
   *
   * For Statement this is populated by the first invocation to
   * getAsyncStatement.
   *
   * For AsyncStatement, this is null at creation time and initialized by the
   * async thread when it calls getAsyncStatement the first time the statement
   * is executed.  (Or in the event of badly formed SQL, every time.)
   */
  sqlite3_stmt *mAsyncStatement;

  /**
   * Initiate asynchronous finalization by dispatching an event to the
   * asynchronous thread to finalize mAsyncStatement.  This acquires a reference
   * to this statement and proxies it back to the connection's owning thread
   * for release purposes.
   *
   * In the event the asynchronous thread is already gone or we otherwise fail
   * to dispatch an event to it we failover to invoking internalAsyncFinalize
   * directly.  (That's what the asynchronous finalizer would have called.)
   *
   * @note You must not call this method from your destructor because its
   *       operation assumes we are still alive.  Call internalAsyncFinalize
   *       directly in that case.
   */
  void asyncFinalize();

  /**
   * Cleanup the async sqlite3_stmt stored in mAsyncStatement if it exists by
   * attempting to dispatch to the asynchronous thread if available, finalizing
   * on this thread if it is not.
   *
   * @note Call this from your destructor, call asyncFinalize otherwise.
   */
  void destructorAsyncFinalize();

  NS_IMETHOD NewBindingParamsArray(mozIStorageBindingParamsArray **_array);
  NS_IMETHOD ExecuteAsync(mozIStorageStatementCallback *aCallback,
                          mozIStoragePendingStatement **_stmt);
  NS_IMETHOD EscapeStringForLIKE(const nsAString &aValue, char16_t aEscapeChar,
                                 nsAString &_escapedString);

  // Needs access to internalAsyncFinalize
  friend class AsyncStatementFinalizer;
};

NS_DEFINE_STATIC_IID_ACCESSOR(StorageBaseStatementInternal,
                              STORAGEBASESTATEMENTINTERNAL_IID)

#define NS_DECL_STORAGEBASESTATEMENTINTERNAL                           \
  virtual Connection *getOwner();                                      \
  virtual int getAsyncStatement(sqlite3_stmt **_stmt) override;        \
  virtual nsresult getAsynchronousStatementData(StatementData &_data)  \
      override;                                                        \
  virtual already_AddRefed<mozIStorageBindingParams> newBindingParams( \
      mozIStorageBindingParamsArray *aOwner) override;

/**
 * Helper macro to implement the proxying implementations.  Because we are
 * implementing methods that are part of mozIStorageBaseStatement and the
 * implementation classes already use NS_DECL_MOZISTORAGEBASESTATEMENT we don't
 * need to provide declaration support.
 */
#define MIX_IMPL(_class, _optionalGuard, _method, _declArgs, _invokeArgs)    \
  NS_IMETHODIMP _class::_method _declArgs {                                  \
    _optionalGuard return StorageBaseStatementInternal::_method _invokeArgs; \
  }

/**
 * Define proxying implementation for the given _class.  If a state invariant
 * needs to be checked and an early return possibly performed, pass the clause
 * to use as _optionalGuard.
 */
#define MIXIN_IMPL_STORAGEBASESTATEMENTINTERNAL(_class, _optionalGuard) \
  MIX_IMPL(_class, _optionalGuard, NewBindingParamsArray,               \
           (mozIStorageBindingParamsArray * *_array), (_array))         \
  MIX_IMPL(_class, _optionalGuard, ExecuteAsync,                        \
           (mozIStorageStatementCallback * aCallback,                   \
            mozIStoragePendingStatement * *_stmt),                      \
           (aCallback, _stmt))                                          \
  MIX_IMPL(_class, _optionalGuard, EscapeStringForLIKE,                 \
           (const nsAString &aValue, char16_t aEscapeChar,              \
            nsAString &_escapedString),                                 \
           (aValue, aEscapeChar, _escapedString))

/**
 * Name-building helper for BIND_GEN_IMPL.
 */
#define BIND_NAME_CONCAT(_nameBit, _concatBit) Bind##_nameBit##_concatBit

/**
 * We have type-specific convenience methods for C++ implementations in
 * two different forms; by index and by name.  The following macro allows
 * us to avoid having to define repetitive things by hand.
 *
 * Because of limitations of macros and our desire to avoid requiring special
 * permutations for the null and blob cases (whose argument count varies),
 * we require that the argument declarations and corresponding invocation
 * usages are passed in.
 *
 * @param _class
 *        The class name.
 * @param _guard
 *        The guard clause to inject.
 * @param _declName
 *        The argument list (with parens) for the ByName variants.
 * @param _declIndex
 *        The argument list (with parens) for the ByIndex variants.
 * @param _invArgs
 *        The invocation argumment list.
 */
#define BIND_GEN_IMPL(_class, _guard, _name, _declName, _declIndex, _invArgs) \
  NS_IMETHODIMP _class::BIND_NAME_CONCAT(_name, ByName) _declName {           \
    _guard mozIStorageBindingParams *params = getParams();                    \
    NS_ENSURE_TRUE(params, NS_ERROR_OUT_OF_MEMORY);                           \
    return params->BIND_NAME_CONCAT(_name, ByName) _invArgs;                  \
  }                                                                           \
  NS_IMETHODIMP _class::BIND_NAME_CONCAT(_name, ByIndex) _declIndex {         \
    _guard mozIStorageBindingParams *params = getParams();                    \
    NS_ENSURE_TRUE(params, NS_ERROR_OUT_OF_MEMORY);                           \
    return params->BIND_NAME_CONCAT(_name, ByIndex) _invArgs;                 \
  }

/**
 * Implement BindByName/BindByIndex for the given class.
 *
 * @param _class The class name.
 * @param _optionalGuard The guard clause to inject.
 */
#define BIND_BASE_IMPLS(_class, _optionalGuard)                            \
  NS_IMETHODIMP _class::BindByName(const nsACString &aName,                \
                                   nsIVariant *aValue) {                   \
    _optionalGuard mozIStorageBindingParams *params = getParams();         \
    NS_ENSURE_TRUE(params, NS_ERROR_OUT_OF_MEMORY);                        \
    return params->BindByName(aName, aValue);                              \
  }                                                                        \
  NS_IMETHODIMP _class::BindByIndex(uint32_t aIndex, nsIVariant *aValue) { \
    _optionalGuard mozIStorageBindingParams *params = getParams();         \
    NS_ENSURE_TRUE(params, NS_ERROR_OUT_OF_MEMORY);                        \
    return params->BindByIndex(aIndex, aValue);                            \
  }

/**
 * Define the various Bind*ByIndex, Bind*ByName stubs that just end up proxying
 * to the params object.
 */
#define BOILERPLATE_BIND_PROXIES(_class, _optionalGuard)                       \
  BIND_BASE_IMPLS(_class, _optionalGuard)                                      \
  BIND_GEN_IMPL(_class, _optionalGuard, UTF8String,                            \
                (const nsACString &aWhere, const nsACString &aValue),          \
                (uint32_t aWhere, const nsACString &aValue), (aWhere, aValue)) \
  BIND_GEN_IMPL(_class, _optionalGuard, String,                                \
                (const nsACString &aWhere, const nsAString &aValue),           \
                (uint32_t aWhere, const nsAString &aValue), (aWhere, aValue))  \
  BIND_GEN_IMPL(_class, _optionalGuard, Double,                                \
                (const nsACString &aWhere, double aValue),                     \
                (uint32_t aWhere, double aValue), (aWhere, aValue))            \
  BIND_GEN_IMPL(_class, _optionalGuard, Int32,                                 \
                (const nsACString &aWhere, int32_t aValue),                    \
                (uint32_t aWhere, int32_t aValue), (aWhere, aValue))           \
  BIND_GEN_IMPL(_class, _optionalGuard, Int64,                                 \
                (const nsACString &aWhere, int64_t aValue),                    \
                (uint32_t aWhere, int64_t aValue), (aWhere, aValue))           \
  BIND_GEN_IMPL(_class, _optionalGuard, Null, (const nsACString &aWhere),      \
                (uint32_t aWhere), (aWhere))                                   \
  BIND_GEN_IMPL(                                                               \
      _class, _optionalGuard, Blob,                                            \
      (const nsACString &aWhere, const uint8_t *aValue, uint32_t aValueSize),  \
      (uint32_t aWhere, const uint8_t *aValue, uint32_t aValueSize),           \
      (aWhere, aValue, aValueSize))                                            \
  BIND_GEN_IMPL(_class, _optionalGuard, StringAsBlob,                          \
                (const nsACString &aWhere, const nsAString &aValue),           \
                (uint32_t aWhere, const nsAString &aValue), (aWhere, aValue))  \
  BIND_GEN_IMPL(_class, _optionalGuard, UTF8StringAsBlob,                      \
                (const nsACString &aWhere, const nsACString &aValue),          \
                (uint32_t aWhere, const nsACString &aValue), (aWhere, aValue)) \
  BIND_GEN_IMPL(                                                               \
      _class, _optionalGuard, AdoptedBlob,                                     \
      (const nsACString &aWhere, uint8_t *aValue, uint32_t aValueSize),        \
      (uint32_t aWhere, uint8_t * aValue, uint32_t aValueSize),                \
      (aWhere, aValue, aValueSize))

}  // namespace storage
}  // namespace mozilla

#endif  // mozilla_storage_StorageBaseStatementInternal_h_