storage/mozIStorageStatement.idl
author Nicholas Nethercote <nnethercote@mozilla.com>
Fri, 16 Feb 2018 17:54:16 +1100
changeset 407868 32d6774930e55be5c03e8d631fc067a995623c1e
parent 321121 059f143b789492d36df1cf20ba6385e16572e139
child 465872 cfd44c936a9b52dc094321ac20a4422ef5b12282
permissions -rw-r--r--
Bug 1438678 - Pass early prefs via shared memory instead of the command line. r=bobowen,jld,glandium. This patch replaces the large -intPrefs/-boolPrefs/-stringPrefs flags with a short-lived, anonymous, shared memory segment that is used to pass the early prefs. Removing the bloat from the command line is nice, but more important is the fact that this will let us pass more prefs at content process start-up, which will allow us to remove the early/late prefs split (bug 1436911). Although this mechanism is only used for prefs, it's conceivable that it could be used for other data that must be received very early by children, and for which the command line isn't ideal. Notable details: - Much of the patch deals with the various platform-specific ways of passing handles/fds to children. - Linux and Mac: we use a fixed fd (8) in combination with the new GeckoChildProcessHost::AddFdToRemap() function (which ensures the child won't close the fd). - Android: like Linux and Mac, but the handles get passed via "parcels" and we use the new SetPrefsFd() function instead of the fixed fd. - Windows: there is no need to duplicate the handle because Windows handles are system-wide. But we do use the new GeckoChildProcessHost::AddHandleToShare() function to add it to the list of inheritable handles. We also ensure that list is processed on all paths (MOZ_SANDBOX with sandbox, MOZ_SANDBOX without sandbox, non-MOZ_SANDBOX) so that the handles are marked as inheritable. The handle is passed via the -prefsHandle flag. The -prefsLen flag is used on all platforms to indicate the size of the shared memory segment. - The patch also moves the serialization/deserialization of the prefs in/out of the shared memory into libpref, which is a better spot for it. (This means Preferences::MustSendToContentProcesses() can be removed.) MozReview-Commit-ID: 8fREEBiYFvc

/* -*- 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/. */

#include "mozIStorageBaseStatement.idl"
%{C++
#include "mozilla/DebugOnly.h"
%}

[ptr] native octetPtr(uint8_t);

/**
 * A SQL statement that can be used for both synchronous and asynchronous
 * purposes.
 */
[scriptable, uuid(5f567c35-6c32-4140-828c-683ea49cfd3a)]
interface mozIStorageStatement : mozIStorageBaseStatement {
  /**
   * Create a clone of this statement, by initializing a new statement
   * with the same connection and same SQL statement as this one.  It
   * does not preserve statement state; that is, if a statement is
   * being executed when it is cloned, the new statement will not be
   * executing.
   */
  mozIStorageStatement clone();

  /*
   * Number of parameters
   */
  readonly attribute unsigned long parameterCount;

  /**
   * Name of nth parameter, if given
   */
  AUTF8String getParameterName(in unsigned long aParamIndex);

  /**
   * Returns the index of the named parameter.
   *
   * @param aName
   *        The name of the parameter you want the index for.  This does not
   *        include the leading ':'.
   * @return the index of the named parameter.
   */
  unsigned long getParameterIndex(in AUTF8String aName);

  /**
   * Number of columns returned
   */
  readonly attribute unsigned long columnCount;

  /**
   * Name of nth column
   */
  AUTF8String getColumnName(in unsigned long aColumnIndex);

  /**
   * Obtains the index of the column with the specified name.
   *
   * @param aName
   *        The name of the column.
   * @return The index of the column with the specified name.
   */
  unsigned long getColumnIndex(in AUTF8String aName);

  /**
   * Reset parameters/statement execution
   */
  void reset();

  /**
   * Execute the query, ignoring any results.  This is accomplished by
   * calling executeStep() once, and then calling reset().
   *
   * Error and last insert info, etc. are available from
   * the mozStorageConnection.
   */
  void execute();

  /**
   * Execute a query, using any currently-bound parameters.  Reset
   * must be called on the statement after the last call of
   * executeStep.
   *
   * @return a boolean indicating whether there are more rows or not;
   *         row data may be accessed using mozIStorageValueArray methods on
   *         the statement.
   */
  boolean executeStep();

  /**
   * Execute a query, using any currently-bound parameters.  Reset is called
   * when no more data is returned.  This method is only available to JavaScript
   * consumers.
   *
   * @deprecated As of Mozilla 1.9.2 in favor of executeStep().
   *
   * @return a boolean indicating whether there are more rows or not.
   *
   * [deprecated] boolean step();
   */

  /**
   * Obtains the current list of named parameters, which are settable.  This
   * property is only available to JavaScript consumers.
   *
   * readonly attribute mozIStorageStatementParams params;
   */

  /**
   * Obtains the current row, with access to all the data members by name.  This
   * property is only available to JavaScript consumers.
   *
   * readonly attribute mozIStorageStatementRow row;
   */

  //////////////////////////////////////////////////////////////////////////////
  //// Copied contents of mozIStorageValueArray

  /**
   * These type values are returned by getTypeOfIndex
   * to indicate what type of value is present at
   * a given column.
   */
  const long VALUE_TYPE_NULL = 0;
  const long VALUE_TYPE_INTEGER = 1;
  const long VALUE_TYPE_FLOAT = 2;
  const long VALUE_TYPE_TEXT = 3;
  const long VALUE_TYPE_BLOB = 4;

  /**
   * The number of entries in the array (each corresponding to a column in the
   * database row)
   */
  readonly attribute unsigned long numEntries;

  /**
   * Indicate the data type of the current result row for the the given column.
   * SQLite will perform type conversion if you ask for a value as a different
   * type than it is stored as.
   *
   * @param aIndex
   *        0-based column index.
   * @return The type of the value at the given column index; one of
   *         VALUE_TYPE_NULL, VALUE_TYPE_INTEGER, VALUE_TYPE_FLOAT,
   *         VALUE_TYPE_TEXT, VALUE_TYPE_BLOB.
   */
  long getTypeOfIndex(in unsigned long aIndex);

  /**
   * Retrieve the contents of a column from the current result row as an
   * integer.
   *
   * @param aIndex
   *        0-based colummn index.
   * @return Column value interpreted as an integer per type conversion rules.
   * @{
   */
  long getInt32(in unsigned long aIndex);
  long long getInt64(in unsigned long aIndex);
  /** @} */
  /**
   * Retrieve the contents of a column from the current result row as a
   * floating point double.
   *
   * @param aIndex
   *        0-based colummn index.
   * @return Column value interpreted as a double per type conversion rules.
   */
  double getDouble(in unsigned long aIndex);
  /**
   * Retrieve the contents of a column from the current result row as a
   * string.
   *
   * @param aIndex
   *        0-based colummn index.
   * @return The value for the result column interpreted as a string.  If the
   *         stored value was NULL, you will get an empty string with IsVoid set
   *         to distinguish it from an explicitly set empty string.
   * @{
   */
  AUTF8String getUTF8String(in unsigned long aIndex);
  AString getString(in unsigned long aIndex);
  /** @} */

  /**
   * Retrieve the contents of a column from the current result row as a
   * blob.
   *
   * @param aIndex
   *        0-based colummn index.
   * @param[out] aDataSize
   *             The number of bytes in the blob.
   * @param[out] aData
   *             The contents of the BLOB.  This will be NULL if aDataSize == 0.
   */
  void getBlob(in unsigned long aIndex, out unsigned long aDataSize, [array,size_is(aDataSize)] out octet aData);

  /**
   * Retrieve the contents of a Blob column from the current result row as a
   * string.
   *
   * @param aIndex
   *        0-based colummn index.
   * @return The value for the result Blob column interpreted as a String.
   *         No encoding conversion is performed.
   */
  AString getBlobAsString(in unsigned long aIndex);

  /**
   * Retrieve the contents of a Blob column from the current result row as a
   * UTF8 string.
   *
   * @param aIndex
   *        0-based colummn index.
   * @return The value for the result Blob column interpreted as a UTF8 String.
   *         No encoding conversion is performed.
   */
  AUTF8String getBlobAsUTF8String(in unsigned long aIndex);

  /**
   * Check whether the given column in the current result row is NULL.
   *
   * @param aIndex
   *        0-based colummn index.
   * @return true if the value for the result column is null.
   */
  boolean getIsNull(in unsigned long aIndex);

  /**
   * Returns a shared string pointer
   */
  [noscript] void getSharedUTF8String(in unsigned long aIndex, out unsigned long aLength, [shared,retval] out string aResult);
  [noscript] void getSharedString(in unsigned long aIndex, out unsigned long aLength, [shared,retval] out wstring aResult);
  [noscript] void getSharedBlob(in unsigned long aIndex, out unsigned long aLength, [shared,retval] out octetPtr aResult);

%{C++
  /**
   * Getters for native code that return their values as
   * the return type, for convenience and sanity.
   *
   * Not virtual; no vtable bloat.
   */

  inline int32_t AsInt32(uint32_t idx) {
    int32_t v = 0;
    mozilla::DebugOnly<nsresult> rv = GetInt32(idx, &v);
    MOZ_ASSERT(NS_SUCCEEDED(rv) || IsNull(idx),
               "Getting value failed, wrong column index?");
    return v;
  }

  inline int64_t AsInt64(uint32_t idx) {
    int64_t v = 0;
    mozilla::DebugOnly<nsresult> rv = GetInt64(idx, &v);
    MOZ_ASSERT(NS_SUCCEEDED(rv) || IsNull(idx),
               "Getting value failed, wrong column index?");
    return v;
  }

  inline double AsDouble(uint32_t idx) {
    double v = 0.0;
    mozilla::DebugOnly<nsresult> rv = GetDouble(idx, &v);
    MOZ_ASSERT(NS_SUCCEEDED(rv) || IsNull(idx),
               "Getting value failed, wrong column index?");
    return v;
  }

  inline const char* AsSharedUTF8String(uint32_t idx, uint32_t *len) {
    const char *str = nullptr;
    *len = 0;
    mozilla::DebugOnly<nsresult> rv = GetSharedUTF8String(idx, len, &str);
    MOZ_ASSERT(NS_SUCCEEDED(rv) || IsNull(idx),
               "Getting value failed, wrong column index?");
    return str;
  }

  inline const char16_t* AsSharedWString(uint32_t idx, uint32_t *len) {
    const char16_t *str = nullptr;
    *len = 0;
    mozilla::DebugOnly<nsresult> rv = GetSharedString(idx, len, &str);
    MOZ_ASSERT(NS_SUCCEEDED(rv) || IsNull(idx),
               "Getting value failed, wrong column index?");
    return str;
  }

  inline const uint8_t* AsSharedBlob(uint32_t idx, uint32_t *len) {
    const uint8_t *blob = nullptr;
    *len = 0;
    mozilla::DebugOnly<nsresult> rv = GetSharedBlob(idx, len, &blob);
    MOZ_ASSERT(NS_SUCCEEDED(rv) || IsNull(idx),
               "Getting value failed, wrong column index?");
    return blob;
  }

  inline bool IsNull(uint32_t idx) {
    bool b = false;
    mozilla::DebugOnly<nsresult> rv = GetIsNull(idx, &b);
    MOZ_ASSERT(NS_SUCCEEDED(rv),
               "Getting value failed, wrong column index?");
    return b;
  }

%}
};