sqlite: add support for SQLite Session Extension

PR-URL: https://github.com/nodejs/node/pull/54181
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

deps/sqlite/sqlite.gyp

@@ -12,6 +12,10 @@
       'xcode_settings': {
         'GCC_SYMBOLS_PRIVATE_EXTERN': 'YES',  # -fvisibility=hidden
       },
+      'defines': [
+        'SQLITE_ENABLE_SESSION',
+        'SQLITE_ENABLE_PREUPDATE_HOOK'
+      ],
       'include_dirs': ['.'],
       'sources': [
         '<@(sqlite_sources)',

doc/api/sqlite.md

@@ -155,6 +155,70 @@ added: v22.5.0
 Compiles a SQL statement into a [prepared statement][]. This method is a wrapper
 around [`sqlite3_prepare_v2()`][].
 
+### `database.createSession([options])`
+
+* `options` {Object} The configuration options for the session.
+  * `table` {string} A specific table to track changes for. By default, changes to all tables are tracked.
+  * `db` {string} Name of the database to track. This is useful when multiple databases have been added using [`ATTACH DATABASE`][]. **Default**: `'main'`.
+* Returns: {Session} A session handle.
+
+Creates and attaches a session to the database. This method is a wrapper around [`sqlite3session_create()`][] and [`sqlite3session_attach()`][].
+
+### `database.applyChangeset(changeset[, options])`
+
+* `changeset` {Uint8Array} A binary changeset or patchset.
+* `options` {Object} The configuration options for how the changes will be applied.
+  * `filter` {Function} Skip changes that, when targeted table name is supplied to this function, return a truthy value.
+    By default, all changes are attempted.
+  * `onConflict` {number} Determines how conflicts are handled. **Default**: `SQLITE_CHANGESET_ABORT`.
+    * `SQLITE_CHANGESET_OMIT`: conflicting changes are omitted.
+    * `SQLITE_CHANGESET_REPLACE`: conflicting changes replace existing values.
+    * `SQLITE_CHANGESET_ABORT`: abort on conflict and roll back databsase.
+* Returns: {boolean} Whether the changeset was applied succesfully without being aborted.
+
+An exception is thrown if the database is not
+open. This method is a wrapper around [`sqlite3changeset_apply()`][].
+
+```js
+const sourceDb = new DatabaseSync(':memory:');
+const targetDb = new DatabaseSync(':memory:');
+
+sourceDb.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
+targetDb.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
+
+const session = sourceDb.createSession();
+
+const insert = sourceDb.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
+insert.run(1, 'hello');
+insert.run(2, 'world');
+
+const changeset = session.changeset();
+targetDb.applyChangeset(changeset);
+// Now that the changeset has been applied, targetDb contains the same data as sourceDb.
+```
+
+## Class: `Session`
+
+### `session.changeset()`
+
+* Returns: {Uint8Array} Binary changeset that can be applied to other databases.
+
+Retrieves a changeset containing all changes since the changeset was created. Can be called multiple times.
+An exception is thrown if the database or the session is not open. This method is a wrapper around [`sqlite3session_changeset()`][].
+
+### `session.patchset()`
+
+* Returns: {Uint8Array} Binary patchset that can be applied to other databases.
+
+Similar to the method above, but generates a more compact patchset. See [Changesets and Patchsets][]
+in the documentation of SQLite. An exception is thrown if the database or the session is not open. This method is a
+wrapper around [`sqlite3session_patchset()`][].
+
+### `session.close()`.
+
+Closes the session. An exception is thrown if the database or the session is not open. This method is a
+wrapper around [`sqlite3session_delete()`][].
+
 ## Class: `StatementSync`
 
 <!-- YAML
@@ -317,8 +381,39 @@ exception.
 | `TEXT`    | {string}             |
 | `BLOB`    | {Uint8Array}         |
 
+## SQLite constants
+
+The following constants are exported by the `node:sqlite` module.
+
+### SQLite Session constants
+
+#### Conflict-resolution constants
+
+The following constants are meant for use with [`database.applyChangeset()`](#databaseapplychangesetchangeset-options).
+
+<table>
+  <tr>
+    <th>Constant</th>
+    <th>Description</th>
+  </tr>
+  <tr>
+    <td><code>SQLITE_CHANGESET_OMIT</code></td>
+    <td>Conflicting changes are omitted.</td>
+  </tr>
+  <tr>
+    <td><code>SQLITE_CHANGESET_REPLACE</code></td>
+    <td>Conflicting changes replace existing values.</td>
+  </tr>
+  <tr>
+    <td><code>SQLITE_CHANGESET_ABORT</code></td>
+    <td>Abort when a change encounters a conflict and roll back databsase.</td>
+  </tr>
+</table>
+
+[Changesets and Patchsets]: https://www.sqlite.org/sessionintro.html#changesets_and_patchsets
 [SQL injection]: https://en.wikipedia.org/wiki/SQL_injection
 [`--experimental-sqlite`]: cli.md#--experimental-sqlite
+[`ATTACH DATABASE`]: https://www.sqlite.org/lang_attach.html
 [`PRAGMA foreign_keys`]: https://www.sqlite.org/pragma.html#pragma_foreign_keys
 [`sqlite3_changes64()`]: https://www.sqlite.org/c3ref/changes.html
 [`sqlite3_close_v2()`]: https://www.sqlite.org/c3ref/close.html
@@ -327,6 +422,12 @@ exception.
 [`sqlite3_last_insert_rowid()`]: https://www.sqlite.org/c3ref/last_insert_rowid.html
 [`sqlite3_prepare_v2()`]: https://www.sqlite.org/c3ref/prepare.html
 [`sqlite3_sql()`]: https://www.sqlite.org/c3ref/expanded_sql.html
+[`sqlite3changeset_apply()`]: https://www.sqlite.org/session/sqlite3changeset_apply.html
+[`sqlite3session_attach()`]: https://www.sqlite.org/session/sqlite3session_attach.html
+[`sqlite3session_changeset()`]: https://www.sqlite.org/session/sqlite3session_changeset.html
+[`sqlite3session_create()`]: https://www.sqlite.org/session/sqlite3session_create.html
+[`sqlite3session_delete()`]: https://www.sqlite.org/session/sqlite3session_delete.html
+[`sqlite3session_patchset()`]: https://www.sqlite.org/session/sqlite3session_patchset.html
 [connection]: https://www.sqlite.org/c3ref/sqlite3.html
 [data types]: https://www.sqlite.org/datatype3.html
 [double-quoted string literals]: https://www.sqlite.org/quirks.html#dblquote

node.gyp

@@ -882,6 +882,7 @@
         # Warn when using deprecated V8 APIs.
         'V8_DEPRECATION_WARNINGS=1',
         'NODE_OPENSSL_SYSTEM_CERT_PATH="<(openssl_system_ca_path)"',
+        "SQLITE_ENABLE_SESSION"
       ],
 
       # - "C4244: conversion from 'type1' to 'type2', possible loss of data"

src/env_properties.h

@@ -160,6 +160,7 @@
   V(fields_string, "fields")                                                   \
   V(file_string, "file")                                                       \
   V(filename_string, "filename")                                               \
+  V(filter_string, "filter")                                                   \
   V(fingerprint256_string, "fingerprint256")                                   \
   V(fingerprint512_string, "fingerprint512")                                   \
   V(fingerprint_string, "fingerprint")                                         \
@@ -246,6 +247,7 @@
   V(onchange_string, "onchange")                                               \
   V(onclienthello_string, "onclienthello")                                     \
   V(oncomplete_string, "oncomplete")                                           \
+  V(onconflict_string, "onConflict")                                           \
   V(onconnection_string, "onconnection")                                       \
   V(ondone_string, "ondone")                                                   \
   V(onerror_string, "onerror")                                                 \
@@ -413,6 +415,7 @@
   V(shutdown_wrap_template, v8::ObjectTemplate)                                \
   V(socketaddress_constructor_template, v8::FunctionTemplate)                  \
   V(sqlite_statement_sync_constructor_template, v8::FunctionTemplate)          \
+  V(sqlite_session_constructor_template, v8::FunctionTemplate)                 \
   V(streambaseentry_ctor_template, v8::FunctionTemplate)                       \
   V(streambaseoutputstream_constructor_template, v8::ObjectTemplate)           \
   V(streamentry_ctor_template, v8::FunctionTemplate)                           \

src/node_sqlite.cc

@@ -22,6 +22,7 @@ using v8::ConstructorBehavior;
 using v8::Context;
 using v8::DontDelete;
 using v8::Exception;
+using v8::Function;
 using v8::FunctionCallback;
 using v8::FunctionCallbackInfo;
 using v8::FunctionTemplate;
@@ -31,6 +32,7 @@ using v8::Local;
 using v8::LocalVector;
 using v8::MaybeLocal;
 using v8::Name;
+using v8::NewStringType;
 using v8::Null;
 using v8::Number;
 using v8::Object;
@@ -51,7 +53,7 @@ using v8::Value;
 #define THROW_AND_RETURN_ON_BAD_STATE(env, condition, msg)                     \
   do {                                                                         \
     if ((condition)) {                                                         \
-      node::THROW_ERR_INVALID_STATE((env), (msg));                             \
+      THROW_ERR_INVALID_STATE((env), (msg));                                   \
       return;                                                                  \
     }                                                                          \
   } while (0)
@@ -121,9 +123,19 @@ DatabaseSync::DatabaseSync(Environment* env,
   }
 }
 
+void DatabaseSync::DeleteSessions() {
+  // all attached sessions need to be deleted before the database is closed
+  // https://www.sqlite.org/session/sqlite3session_create.html
+  for (auto* session : sessions_) {
+    sqlite3session_delete(session);
+  }
+  sessions_.clear();
+}
+
 DatabaseSync::~DatabaseSync() {
   if (IsOpen()) {
     FinalizeStatements();
+    DeleteSessions();
     sqlite3_close_v2(connection_);
     connection_ = nullptr;
   }
@@ -137,7 +149,7 @@ void DatabaseSync::MemoryInfo(MemoryTracker* tracker) const {
 
 bool DatabaseSync::Open() {
   if (IsOpen()) {
-    node::THROW_ERR_INVALID_STATE(env(), "database is already open");
+    THROW_ERR_INVALID_STATE(env(), "database is already open");
     return false;
   }
 
@@ -204,21 +216,21 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
   }
 
   if (!args[0]->IsString()) {
-    node::THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
+    THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
                                "The \"path\" argument must be a string.");
     return;
   }
 
   std::string location =
-      node::Utf8Value(env->isolate(), args[0].As<String>()).ToString();
+      Utf8Value(env->isolate(), args[0].As<String>()).ToString();
   DatabaseOpenConfiguration open_config(std::move(location));
 
   bool open = true;
 
   if (args.Length() > 1) {
     if (!args[1]->IsObject()) {
-      node::THROW_ERR_INVALID_ARG_TYPE(
-          env->isolate(), "The \"options\" argument must be an object.");
+      THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
+                                 "The \"options\" argument must be an object.");
       return;
     }
 
@@ -230,7 +242,7 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
     }
     if (!open_v->IsUndefined()) {
       if (!open_v->IsBoolean()) {
-        node::THROW_ERR_INVALID_ARG_TYPE(
+        THROW_ERR_INVALID_ARG_TYPE(
             env->isolate(), "The \"options.open\" argument must be a boolean.");
         return;
       }
@@ -245,7 +257,7 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
     }
     if (!read_only_v->IsUndefined()) {
       if (!read_only_v->IsBoolean()) {
-        node::THROW_ERR_INVALID_ARG_TYPE(
+        THROW_ERR_INVALID_ARG_TYPE(
             env->isolate(),
             "The \"options.readOnly\" argument must be a boolean.");
         return;
@@ -262,7 +274,7 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
     }
     if (!enable_foreign_keys_v->IsUndefined()) {
       if (!enable_foreign_keys_v->IsBoolean()) {
-        node::THROW_ERR_INVALID_ARG_TYPE(
+        THROW_ERR_INVALID_ARG_TYPE(
             env->isolate(),
             "The \"options.enableForeignKeyConstraints\" argument must be a "
             "boolean.");
@@ -281,7 +293,7 @@ void DatabaseSync::New(const FunctionCallbackInfo<Value>& args) {
     }
     if (!enable_dqs_v->IsUndefined()) {
       if (!enable_dqs_v->IsBoolean()) {
-        node::THROW_ERR_INVALID_ARG_TYPE(
+        THROW_ERR_INVALID_ARG_TYPE(
             env->isolate(),
             "The \"options.enableDoubleQuotedStringLiterals\" argument must be "
             "a boolean.");
@@ -306,6 +318,7 @@ void DatabaseSync::Close(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   THROW_AND_RETURN_ON_BAD_STATE(env, !db->IsOpen(), "database is not open");
   db->FinalizeStatements();
+  db->DeleteSessions();
   int r = sqlite3_close_v2(db->connection_);
   CHECK_ERROR_OR_THROW(env->isolate(), db->connection_, r, SQLITE_OK, void());
   db->connection_ = nullptr;
@@ -318,12 +331,12 @@ void DatabaseSync::Prepare(const FunctionCallbackInfo<Value>& args) {
   THROW_AND_RETURN_ON_BAD_STATE(env, !db->IsOpen(), "database is not open");
 
   if (!args[0]->IsString()) {
-    node::THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
+    THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
                                "The \"sql\" argument must be a string.");
     return;
   }
 
-  node::Utf8Value sql(env->isolate(), args[0].As<String>());
+  Utf8Value sql(env->isolate(), args[0].As<String>());
   sqlite3_stmt* s = nullptr;
   int r = sqlite3_prepare_v2(db->connection_, *sql, -1, &s, 0);
   CHECK_ERROR_OR_THROW(env->isolate(), db->connection_, r, SQLITE_OK, void());
@@ -339,16 +352,179 @@ void DatabaseSync::Exec(const FunctionCallbackInfo<Value>& args) {
   THROW_AND_RETURN_ON_BAD_STATE(env, !db->IsOpen(), "database is not open");
 
   if (!args[0]->IsString()) {
-    node::THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
+    THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
                                "The \"sql\" argument must be a string.");
     return;
   }
 
-  node::Utf8Value sql(env->isolate(), args[0].As<String>());
+  Utf8Value sql(env->isolate(), args[0].As<String>());
   int r = sqlite3_exec(db->connection_, *sql, nullptr, nullptr, nullptr);
   CHECK_ERROR_OR_THROW(env->isolate(), db->connection_, r, SQLITE_OK, void());
 }
 
+void DatabaseSync::CreateSession(const FunctionCallbackInfo<Value>& args) {
+  std::string table;
+  std::string db_name = "main";
+
+  Environment* env = Environment::GetCurrent(args);
+  if (args.Length() > 0) {
+    if (!args[0]->IsObject()) {
+      THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
+                                 "The \"options\" argument must be an object.");
+      return;
+    }
+
+    Local<Object> options = args[0].As<Object>();
+
+    Local<String> table_key = FIXED_ONE_BYTE_STRING(env->isolate(), "table");
+    if (options->HasOwnProperty(env->context(), table_key).FromJust()) {
+      Local<Value> table_value;
+      if (!options->Get(env->context(), table_key).ToLocal(&table_value)) {
+        return;
+      }
+
+      if (table_value->IsString()) {
+        String::Utf8Value str(env->isolate(), table_value);
+        table = *str;
+      } else {
+        THROW_ERR_INVALID_ARG_TYPE(
+            env->isolate(), "The \"options.table\" argument must be a string.");
+        return;
+      }
+    }
+
+    Local<String> db_key =
+        String::NewFromUtf8(env->isolate(), "db", NewStringType::kNormal)
+            .ToLocalChecked();
+    if (options->HasOwnProperty(env->context(), db_key).FromJust()) {
+      Local<Value> db_value =
+          options->Get(env->context(), db_key).ToLocalChecked();
+      if (db_value->IsString()) {
+        String::Utf8Value str(env->isolate(), db_value);
+        db_name = std::string(*str);
+      } else {
+        THROW_ERR_INVALID_ARG_TYPE(
+            env->isolate(), "The \"options.db\" argument must be a string.");
+        return;
+      }
+    }
+  }
+
+  DatabaseSync* db;
+  ASSIGN_OR_RETURN_UNWRAP(&db, args.This());
+  THROW_AND_RETURN_ON_BAD_STATE(env, !db->IsOpen(), "database is not open");
+
+  sqlite3_session* pSession;
+  int r = sqlite3session_create(db->connection_, db_name.c_str(), &pSession);
+  CHECK_ERROR_OR_THROW(env->isolate(), db->connection_, r, SQLITE_OK, void());
+  db->sessions_.insert(pSession);
+
+  r = sqlite3session_attach(pSession, table == "" ? nullptr : table.c_str());
+  CHECK_ERROR_OR_THROW(env->isolate(), db->connection_, r, SQLITE_OK, void());
+
+  BaseObjectPtr<Session> session =
+      Session::Create(env, BaseObjectWeakPtr<DatabaseSync>(db), pSession);
+  args.GetReturnValue().Set(session->object());
+}
+
+// the reason for using static functions here is that SQLite needs a
+// function pointer
+static std::function<int()> conflictCallback;
+
+static int xConflict(void* pCtx, int eConflict, sqlite3_changeset_iter* pIter) {
+  if (!conflictCallback) return SQLITE_CHANGESET_ABORT;
+  return conflictCallback();
+}
+
+static std::function<bool(std::string)> filterCallback;
+
+static int xFilter(void* pCtx, const char* zTab) {
+  if (!filterCallback) return 1;
+
+  return filterCallback(zTab) ? 1 : 0;
+}
+
+void DatabaseSync::ApplyChangeset(const FunctionCallbackInfo<Value>& args) {
+  conflictCallback = nullptr;
+  filterCallback = nullptr;
+
+  DatabaseSync* db;
+  ASSIGN_OR_RETURN_UNWRAP(&db, args.This());
+  Environment* env = Environment::GetCurrent(args);
+  THROW_AND_RETURN_ON_BAD_STATE(env, !db->IsOpen(), "database is not open");
+
+  if (!args[0]->IsUint8Array()) {
+    THROW_ERR_INVALID_ARG_TYPE(
+        env->isolate(), "The \"changeset\" argument must be a Uint8Array.");
+    return;
+  }
+
+  if (args.Length() > 1 && !args[1]->IsUndefined()) {
+    if (!args[1]->IsObject()) {
+      THROW_ERR_INVALID_ARG_TYPE(env->isolate(),
+                                 "The \"options\" argument must be an object.");
+      return;
+    }
+
+    Local<Object> options = args[1].As<Object>();
+    Local<Value> conflictValue =
+        options->Get(env->context(), env->onconflict_string()).ToLocalChecked();
+
+    if (!conflictValue->IsUndefined()) {
+      if (!conflictValue->IsNumber()) {
+        THROW_ERR_INVALID_ARG_TYPE(
+            env->isolate(),
+            "The \"options.onConflict\" argument must be a number.");
+        return;
+      }
+
+      int conflictInt = conflictValue->Int32Value(env->context()).FromJust();
+      conflictCallback = [conflictInt]() -> int { return conflictInt; };
+    }
+
+    if (options->HasOwnProperty(env->context(), env->filter_string())
+            .FromJust()) {
+      Local<Value> filterValue =
+          options->Get(env->context(), env->filter_string()).ToLocalChecked();
+
+      if (!filterValue->IsFunction()) {
+        THROW_ERR_INVALID_ARG_TYPE(
+            env->isolate(),
+            "The \"options.filter\" argument must be a function.");
+        return;
+      }
+
+      Local<Function> filterFunc = filterValue.As<Function>();
+
+      filterCallback = [env, filterFunc](std::string item) -> bool {
+        Local<Value> argv[] = {String::NewFromUtf8(env->isolate(),
+                                                   item.c_str(),
+                                                   NewStringType::kNormal)
+                                   .ToLocalChecked()};
+        Local<Value> result =
+            filterFunc->Call(env->context(), Null(env->isolate()), 1, argv)
+                .ToLocalChecked();
+        return result->BooleanValue(env->isolate());
+      };
+    }
+  }
+
+  ArrayBufferViewContents<uint8_t> buf(args[0]);
+  int r = sqlite3changeset_apply(
+      db->connection_,
+      buf.length(),
+      const_cast<void*>(static_cast<const void*>(buf.data())),
+      xFilter,
+      xConflict,
+      nullptr);
+  if (r == SQLITE_ABORT) {
+    args.GetReturnValue().Set(false);
+    return;
+  }
+  CHECK_ERROR_OR_THROW(env->isolate(), db->connection_, r, SQLITE_OK, void());
+  args.GetReturnValue().Set(true);
+}
+
 StatementSync::StatementSync(Environment* env,
                              Local<Object> object,
                              DatabaseSync* db,
@@ -412,7 +588,7 @@ bool StatementSync::BindParams(const FunctionCallbackInfo<Value>& args) {
         if (insertion.second == false) {
           auto existing_full_name = (*insertion.first).second;
           if (full_name != existing_full_name) {
-            node::THROW_ERR_INVALID_STATE(
+            THROW_ERR_INVALID_STATE(
                 env(),
                 "Cannot create bare named parameter '%s' because of "
                 "conflicting names '%s' and '%s'.",
@@ -432,7 +608,7 @@ bool StatementSync::BindParams(const FunctionCallbackInfo<Value>& args) {
         return false;
       }
 
-      node::Utf8Value utf8_key(env()->isolate(), key);
+      Utf8Value utf8_key(env()->isolate(), key);
       int r = sqlite3_bind_parameter_index(statement_, *utf8_key);
       if (r == 0) {
         if (allow_bare_named_params_) {
@@ -444,7 +620,7 @@ bool StatementSync::BindParams(const FunctionCallbackInfo<Value>& args) {
         }
 
         if (r == 0) {
-          node::THROW_ERR_INVALID_STATE(
+          THROW_ERR_INVALID_STATE(
               env(), "Unknown named parameter '%s'", *utf8_key);
           return false;
         }
@@ -488,7 +664,7 @@ bool StatementSync::BindValue(const Local<Value>& value, const int index) {
     double val = value.As<Number>()->Value();
     r = sqlite3_bind_double(statement_, index, val);
   } else if (value->IsString()) {
-    node::Utf8Value val(env()->isolate(), value.As<String>());
+    Utf8Value val(env()->isolate(), value.As<String>());
     r = sqlite3_bind_text(
         statement_, index, *val, val.length(), SQLITE_TRANSIENT);
   } else if (value->IsNull()) {
@@ -501,13 +677,12 @@ bool StatementSync::BindValue(const Local<Value>& value, const int index) {
     bool lossless;
     int64_t as_int = value.As<BigInt>()->Int64Value(&lossless);
     if (!lossless) {
-      node::THROW_ERR_INVALID_ARG_VALUE(env(),
-                                        "BigInt value is too large to bind.");
+      THROW_ERR_INVALID_ARG_VALUE(env(), "BigInt value is too large to bind.");
       return false;
     }
     r = sqlite3_bind_int64(statement_, index, as_int);
   } else {
-    node::THROW_ERR_INVALID_ARG_TYPE(
+    THROW_ERR_INVALID_ARG_TYPE(
         env()->isolate(),
         "Provided value cannot be bound to SQLite parameter %d.",
         index);
@@ -564,8 +739,7 @@ MaybeLocal<Value> StatementSync::ColumnToValue(const int column) {
 MaybeLocal<Name> StatementSync::ColumnNameToName(const int column) {
   const char* col_name = sqlite3_column_name(statement_, column);
   if (col_name == nullptr) {
-    node::THROW_ERR_INVALID_STATE(
-        env(), "Cannot get name of column %d", column);
+    THROW_ERR_INVALID_STATE(env(), "Cannot get name of column %d", column);
     return MaybeLocal<Name>();
   }
 
@@ -591,32 +765,23 @@ void StatementSync::All(const FunctionCallbackInfo<Value>& args) {
   auto reset = OnScopeLeave([&]() { sqlite3_reset(stmt->statement_); });
   int num_cols = sqlite3_column_count(stmt->statement_);
   LocalVector<Value> rows(isolate);
-  LocalVector<Name> row_keys(isolate);
   while ((r = sqlite3_step(stmt->statement_)) == SQLITE_ROW) {
-    if (row_keys.size() == 0) {
+    LocalVector<Name> row_keys(isolate);
     row_keys.reserve(num_cols);
+    LocalVector<Value> row_values(isolate);
+    row_values.reserve(num_cols);
 
     for (int i = 0; i < num_cols; ++i) {
       Local<Name> key;
       if (!stmt->ColumnNameToName(i).ToLocal(&key)) return;
-        row_keys.emplace_back(key);
-      }
-    }
-
-    LocalVector<Value> row_values(isolate);
-    row_values.reserve(num_cols);
-
-    for (size_t i = 0; i < row_keys.size(); ++i) {
       Local<Value> val;
       if (!stmt->ColumnToValue(i).ToLocal(&val)) return;
+      row_keys.emplace_back(key);
       row_values.emplace_back(val);
     }
 
-    Local<Object> row = Object::New(isolate,
-                                    Null(isolate),
-                                    row_keys.data(),
-                                    row_values.data(),
-                                    row_keys.size());
+    Local<Object> row = Object::New(
+        isolate, Null(isolate), row_keys.data(), row_values.data(), num_cols);
     rows.emplace_back(row);
   }
 
@@ -766,7 +931,7 @@ void StatementSync::SetAllowBareNamedParameters(
       env, stmt->IsFinalized(), "statement has been finalized");
 
   if (!args[0]->IsBoolean()) {
-    node::THROW_ERR_INVALID_ARG_TYPE(
+    THROW_ERR_INVALID_ARG_TYPE(
         env->isolate(),
         "The \"allowBareNamedParameters\" argument must be a boolean.");
     return;
@@ -783,7 +948,7 @@ void StatementSync::SetReadBigInts(const FunctionCallbackInfo<Value>& args) {
       env, stmt->IsFinalized(), "statement has been finalized");
 
   if (!args[0]->IsBoolean()) {
-    node::THROW_ERR_INVALID_ARG_TYPE(
+    THROW_ERR_INVALID_ARG_TYPE(
         env->isolate(), "The \"readBigInts\" argument must be a boolean.");
     return;
   }
@@ -792,7 +957,7 @@ void StatementSync::SetReadBigInts(const FunctionCallbackInfo<Value>& args) {
 }
 
 void IllegalConstructor(const FunctionCallbackInfo<Value>& args) {
-  node::THROW_ERR_ILLEGAL_CONSTRUCTOR(Environment::GetCurrent(args));
+  THROW_ERR_ILLEGAL_CONSTRUCTOR(Environment::GetCurrent(args));
 }
 
 static inline void SetSideEffectFreeGetter(
@@ -858,6 +1023,100 @@ BaseObjectPtr<StatementSync> StatementSync::Create(Environment* env,
   return MakeBaseObject<StatementSync>(env, obj, db, stmt);
 }
 
+Session::Session(Environment* env,
+                 Local<Object> object,
+                 BaseObjectWeakPtr<DatabaseSync> database,
+                 sqlite3_session* session)
+    : BaseObject(env, object),
+      session_(session),
+      database_(std::move(database)) {
+  MakeWeak();
+}
+
+Session::~Session() {
+  Delete();
+}
+
+BaseObjectPtr<Session> Session::Create(Environment* env,
+                                       BaseObjectWeakPtr<DatabaseSync> database,
+                                       sqlite3_session* session) {
+  Local<Object> obj;
+  if (!GetConstructorTemplate(env)
+           ->InstanceTemplate()
+           ->NewInstance(env->context())
+           .ToLocal(&obj)) {
+    return BaseObjectPtr<Session>();
+  }
+
+  return MakeBaseObject<Session>(env, obj, std::move(database), session);
+}
+
+Local<FunctionTemplate> Session::GetConstructorTemplate(Environment* env) {
+  Local<FunctionTemplate> tmpl = env->sqlite_session_constructor_template();
+  if (tmpl.IsEmpty()) {
+    Isolate* isolate = env->isolate();
+    tmpl = NewFunctionTemplate(isolate, IllegalConstructor);
+    tmpl->SetClassName(FIXED_ONE_BYTE_STRING(env->isolate(), "Session"));
+    tmpl->InstanceTemplate()->SetInternalFieldCount(
+        Session::kInternalFieldCount);
+    SetProtoMethod(isolate,
+                   tmpl,
+                   "changeset",
+                   Session::Changeset<sqlite3session_changeset>);
+    SetProtoMethod(
+        isolate, tmpl, "patchset", Session::Changeset<sqlite3session_patchset>);
+    SetProtoMethod(isolate, tmpl, "close", Session::Close);
+    env->set_sqlite_session_constructor_template(tmpl);
+  }
+  return tmpl;
+}
+
+void Session::MemoryInfo(MemoryTracker* tracker) const {}
+
+template <Sqlite3ChangesetGenFunc sqliteChangesetFunc>
+void Session::Changeset(const FunctionCallbackInfo<Value>& args) {
+  Session* session;
+  ASSIGN_OR_RETURN_UNWRAP(&session, args.This());
+  Environment* env = Environment::GetCurrent(args);
+  sqlite3* db = session->database_ ? session->database_->connection_ : nullptr;
+  THROW_AND_RETURN_ON_BAD_STATE(
+      env, !session->database_->IsOpen(), "database is not open");
+  THROW_AND_RETURN_ON_BAD_STATE(
+      env, session->session_ == nullptr, "session is not open");
+
+  int nChangeset;
+  void* pChangeset;
+  int r = sqliteChangesetFunc(session->session_, &nChangeset, &pChangeset);
+  CHECK_ERROR_OR_THROW(env->isolate(), db, r, SQLITE_OK, void());
+
+  auto freeChangeset = OnScopeLeave([&] { sqlite3_free(pChangeset); });
+
+  Local<ArrayBuffer> buffer = ArrayBuffer::New(env->isolate(), nChangeset);
+  std::memcpy(buffer->GetBackingStore()->Data(), pChangeset, nChangeset);
+  Local<Uint8Array> uint8Array = Uint8Array::New(buffer, 0, nChangeset);
+
+  args.GetReturnValue().Set(uint8Array);
+}
+
+void Session::Close(const FunctionCallbackInfo<Value>& args) {
+  Session* session;
+  ASSIGN_OR_RETURN_UNWRAP(&session, args.This());
+  Environment* env = Environment::GetCurrent(args);
+  THROW_AND_RETURN_ON_BAD_STATE(
+      env, !session->database_->IsOpen(), "database is not open");
+  THROW_AND_RETURN_ON_BAD_STATE(
+      env, session->session_ == nullptr, "session is not open");
+
+  session->Delete();
+}
+
+void Session::Delete() {
+  if (!database_ || !database_->connection_ || session_ == nullptr) return;
+  sqlite3session_delete(session_);
+  database_->sessions_.erase(session_);
+  session_ = nullptr;
+}
+
 static void Initialize(Local<Object> target,
                        Local<Value> unused,
                        Local<Context> context,
@@ -873,11 +1132,19 @@ static void Initialize(Local<Object> target,
   SetProtoMethod(isolate, db_tmpl, "close", DatabaseSync::Close);
   SetProtoMethod(isolate, db_tmpl, "prepare", DatabaseSync::Prepare);
   SetProtoMethod(isolate, db_tmpl, "exec", DatabaseSync::Exec);
+  SetProtoMethod(
+      isolate, db_tmpl, "createSession", DatabaseSync::CreateSession);
+  SetProtoMethod(
+      isolate, db_tmpl, "applyChangeset", DatabaseSync::ApplyChangeset);
   SetConstructorFunction(context, target, "DatabaseSync", db_tmpl);
   SetConstructorFunction(context,
                          target,
                          "StatementSync",
                          StatementSync::GetConstructorTemplate(env));
+
+  NODE_DEFINE_CONSTANT(target, SQLITE_CHANGESET_OMIT);
+  NODE_DEFINE_CONSTANT(target, SQLITE_CHANGESET_REPLACE);
+  NODE_DEFINE_CONSTANT(target, SQLITE_CHANGESET_ABORT);
 }
 
 }  // namespace sqlite

src/node_sqlite.h

@@ -56,6 +56,8 @@ class DatabaseSync : public BaseObject {
   static void Close(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Prepare(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Exec(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void CreateSession(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void ApplyChangeset(const v8::FunctionCallbackInfo<v8::Value>& args);
   void FinalizeStatements();
   void UntrackStatement(StatementSync* statement);
   bool IsOpen();
@@ -66,11 +68,16 @@ class DatabaseSync : public BaseObject {
 
  private:
   bool Open();
+  void DeleteSessions();
 
   ~DatabaseSync() override;
   DatabaseOpenConfiguration open_config_;
   sqlite3* connection_;
+
+  std::set<sqlite3_session*> sessions_;
   std::unordered_set<StatementSync*> statements_;
+
+  friend class Session;
 };
 
 class StatementSync : public BaseObject {
@@ -113,6 +120,34 @@ class StatementSync : public BaseObject {
   v8::MaybeLocal<v8::Name> ColumnNameToName(const int column);
 };
 
+using Sqlite3ChangesetGenFunc = int (*)(sqlite3_session*, int*, void**);
+
+class Session : public BaseObject {
+ public:
+  Session(Environment* env,
+          v8::Local<v8::Object> object,
+          BaseObjectWeakPtr<DatabaseSync> database,
+          sqlite3_session* session);
+  ~Session() override;
+  template <Sqlite3ChangesetGenFunc sqliteChangesetFunc>
+  static void Changeset(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void Close(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static v8::Local<v8::FunctionTemplate> GetConstructorTemplate(
+      Environment* env);
+  static BaseObjectPtr<Session> Create(Environment* env,
+                                       BaseObjectWeakPtr<DatabaseSync> database,
+                                       sqlite3_session* session);
+
+  void MemoryInfo(MemoryTracker* tracker) const override;
+  SET_MEMORY_INFO_NAME(Session)
+  SET_SELF_SIZE(Session)
+
+ private:
+  void Delete();
+  sqlite3_session* session_;
+  BaseObjectWeakPtr<DatabaseSync> database_;  // The Parent Database
+};
+
 }  // namespace sqlite
 }  // namespace node
 

test/parallel/test-sqlite-session.js

@@ -0,0 +1,384 @@
+// Flags: --experimental-sqlite
+'use strict';
+require('../common');
+const {
+  DatabaseSync,
+  SQLITE_CHANGESET_OMIT,
+  SQLITE_CHANGESET_REPLACE,
+  SQLITE_CHANGESET_ABORT
+} = require('node:sqlite');
+const { test, suite } = require('node:test');
+
+/**
+ * Convenience wrapper around assert.deepStrictEqual that sets a null
+ * prototype to the expected object.
+ */
+function deepStrictEqual(t) {
+  return (actual, expected, message) => {
+    if (Array.isArray(expected)) {
+      expected = expected.map((obj) => ({ ...obj, __proto__: null }));
+    } else if (typeof expected === 'object') {
+      expected = { ...expected, __proto__: null };
+    }
+    t.assert.deepStrictEqual(actual, expected, message);
+  };
+}
+
+test('creating and applying a changeset', (t) => {
+  const createDataTableSql = `
+      CREATE TABLE data(
+        key INTEGER PRIMARY KEY,
+        value TEXT
+      ) STRICT`;
+
+  const createDatabase = () => {
+    const database = new DatabaseSync(':memory:');
+    database.exec(createDataTableSql);
+    return database;
+  };
+
+  const databaseFrom = createDatabase();
+  const session = databaseFrom.createSession();
+
+  const select = 'SELECT * FROM data ORDER BY key';
+
+  const insert = databaseFrom.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
+  insert.run(1, 'hello');
+  insert.run(2, 'world');
+
+  const databaseTo = createDatabase();
+
+  t.assert.strictEqual(databaseTo.applyChangeset(session.changeset()), true);
+  deepStrictEqual(t)(
+    databaseFrom.prepare(select).all(),
+    databaseTo.prepare(select).all()
+  );
+});
+
+test('database.createSession() - closed database results in exception', (t) => {
+  const database = new DatabaseSync(':memory:');
+  database.close();
+  t.assert.throws(() => {
+    database.createSession();
+  }, {
+    name: 'Error',
+    message: 'database is not open',
+  });
+});
+
+test('session.changeset() - closed database results in exception', (t) => {
+  const database = new DatabaseSync(':memory:');
+  const session = database.createSession();
+  database.close();
+  t.assert.throws(() => {
+    session.changeset();
+  }, {
+    name: 'Error',
+    message: 'database is not open',
+  });
+});
+
+test('database.applyChangeset() - closed database results in exception', (t) => {
+  const database = new DatabaseSync(':memory:');
+  const session = database.createSession();
+  const changeset = session.changeset();
+  database.close();
+  t.assert.throws(() => {
+    database.applyChangeset(changeset);
+  }, {
+    name: 'Error',
+    message: 'database is not open',
+  });
+});
+
+test('database.createSession() - use table option to track specific table', (t) => {
+  const database1 = new DatabaseSync(':memory:');
+  const database2 = new DatabaseSync(':memory:');
+
+  const createData1TableSql = `CREATE TABLE data1 (
+      key INTEGER PRIMARY KEY,
+      value TEXT
+    ) STRICT
+    `;
+  const createData2TableSql = `CREATE TABLE data2 (
+      key INTEGER PRIMARY KEY,
+      value TEXT
+    ) STRICT
+    `;
+  database1.exec(createData1TableSql);
+  database1.exec(createData2TableSql);
+  database2.exec(createData1TableSql);
+  database2.exec(createData2TableSql);
+
+  const session = database1.createSession({
+    table: 'data1'
+  });
+  const insert1 = database1.prepare('INSERT INTO data1 (key, value) VALUES (?, ?)');
+  insert1.run(1, 'hello');
+  insert1.run(2, 'world');
+  const insert2 = database1.prepare('INSERT INTO data2 (key, value) VALUES (?, ?)');
+  insert2.run(1, 'hello');
+  insert2.run(2, 'world');
+  const select1 = 'SELECT * FROM data1 ORDER BY key';
+  const select2 = 'SELECT * FROM data2 ORDER BY key';
+  t.assert.strictEqual(database2.applyChangeset(session.changeset()), true);
+  deepStrictEqual(t)(
+    database1.prepare(select1).all(),
+    database2.prepare(select1).all());  // data1 table should be equal
+  deepStrictEqual(t)(database2.prepare(select2).all(), []);  // data2 should be empty in database2
+  t.assert.strictEqual(database1.prepare(select2).all().length, 2);  // data1 should have values in database1
+});
+
+suite('conflict resolution', () => {
+  const prepareConflict = () => {
+    const database1 = new DatabaseSync(':memory:');
+    const database2 = new DatabaseSync(':memory:');
+
+    const createDataTableSql = `CREATE TABLE data (
+        key INTEGER PRIMARY KEY,
+        value TEXT
+      ) STRICT
+      `;
+    database1.exec(createDataTableSql);
+    database2.exec(createDataTableSql);
+
+    const insertSql = 'INSERT INTO data (key, value) VALUES (?, ?)';
+    const session = database1.createSession();
+    database1.prepare(insertSql).run(1, 'hello');
+    database1.prepare(insertSql).run(2, 'foo');
+    database2.prepare(insertSql).run(1, 'world');
+    return {
+      database2,
+      changeset: session.changeset()
+    };
+  };
+
+  test('database.applyChangeset() - conflict with default behavior (abort)', (t) => {
+    const { database2, changeset } = prepareConflict();
+    // When changeset is aborted due to a conflict, applyChangeset should return false
+    t.assert.strictEqual(database2.applyChangeset(changeset), false);
+    deepStrictEqual(t)(
+      database2.prepare('SELECT value from data').all(),
+      [{ value: 'world' }]);  // unchanged
+  });
+
+  test('database.applyChangeset() - conflict with SQLITE_CHANGESET_ABORT', (t) => {
+    const { database2, changeset } = prepareConflict();
+    const result = database2.applyChangeset(changeset, {
+      onConflict: SQLITE_CHANGESET_ABORT
+    });
+    // When changeset is aborted due to a conflict, applyChangeset should return false
+    t.assert.strictEqual(result, false);
+    deepStrictEqual(t)(
+      database2.prepare('SELECT value from data').all(),
+      [{ value: 'world' }]);  // unchanged
+  });
+
+  test('database.applyChangeset() - conflict with SQLITE_CHANGESET_REPLACE', (t) => {
+    const { database2, changeset } = prepareConflict();
+    const result = database2.applyChangeset(changeset, {
+      onConflict: SQLITE_CHANGESET_REPLACE
+    });
+    // Not aborted due to conflict, so should return true
+    t.assert.strictEqual(result, true);
+    deepStrictEqual(t)(
+      database2.prepare('SELECT value from data ORDER BY key').all(),
+      [{ value: 'hello' }, { value: 'foo' }]);  // replaced
+  });
+
+  test('database.applyChangeset() - conflict with SQLITE_CHANGESET_OMIT', (t) => {
+    const { database2, changeset } = prepareConflict();
+    const result = database2.applyChangeset(changeset, {
+      onConflict: SQLITE_CHANGESET_OMIT
+    });
+    // Not aborted due to conflict, so should return true
+    t.assert.strictEqual(result, true);
+    deepStrictEqual(t)(
+      database2.prepare('SELECT value from data ORDER BY key ASC').all(),
+      [{ value: 'world' }, { value: 'foo' }]);  // Conflicting change omitted
+  });
+});
+
+test('session related constants are defined', (t) => {
+  t.assert.strictEqual(SQLITE_CHANGESET_OMIT, 0);
+  t.assert.strictEqual(SQLITE_CHANGESET_REPLACE, 1);
+  t.assert.strictEqual(SQLITE_CHANGESET_ABORT, 2);
+});
+
+test('database.createSession() - filter changes', (t) => {
+  const database1 = new DatabaseSync(':memory:');
+  const database2 = new DatabaseSync(':memory:');
+  const createTableSql = 'CREATE TABLE data1(key INTEGER PRIMARY KEY); CREATE TABLE data2(key INTEGER PRIMARY KEY);';
+  database1.exec(createTableSql);
+  database2.exec(createTableSql);
+
+  const session = database1.createSession();
+
+  database1.exec('INSERT INTO data1 (key) VALUES (1), (2), (3)');
+  database1.exec('INSERT INTO data2 (key) VALUES (1), (2), (3), (4), (5)');
+
+  database2.applyChangeset(session.changeset(), {
+    filter: (tableName) => tableName === 'data2'
+  });
+
+  const data1Rows = database2.prepare('SELECT * FROM data1').all();
+  const data2Rows = database2.prepare('SELECT * FROM data2').all();
+
+  // Expect no rows since all changes were filtered out
+  t.assert.strictEqual(data1Rows.length, 0);
+  // Expect 5 rows since these changes were not filtered out
+  t.assert.strictEqual(data2Rows.length, 5);
+});
+
+test('database.createSession() - specify other database', (t) => {
+  const database = new DatabaseSync(':memory:');
+  const session = database.createSession();
+  const sessionMain = database.createSession({
+    db: 'main'
+  });
+  const sessionTest = database.createSession({
+    db: 'test'
+  });
+  database.exec('CREATE TABLE data (key INTEGER PRIMARY KEY)');
+  database.exec('INSERT INTO data (key) VALUES (1)');
+  t.assert.notStrictEqual(session.changeset().length, 0);
+  t.assert.notStrictEqual(sessionMain.changeset().length, 0);
+  // Since this session is attached to a different database, its changeset should be empty
+  t.assert.strictEqual(sessionTest.changeset().length, 0);
+});
+
+test('database.createSession() - wrong arguments', (t) => {
+  const database = new DatabaseSync(':memory:');
+  t.assert.throws(() => {
+    database.createSession(null);
+  }, {
+    name: 'TypeError',
+    message: 'The "options" argument must be an object.'
+  });
+
+  t.assert.throws(() => {
+    database.createSession({
+      table: 123
+    });
+  }, {
+    name: 'TypeError',
+    message: 'The "options.table" argument must be a string.'
+  });
+
+  t.assert.throws(() => {
+    database.createSession({
+      db: 123
+    });
+  }, {
+    name: 'TypeError',
+    message: 'The "options.db" argument must be a string.'
+  });
+});
+
+test('database.applyChangeset() - wrong arguments', (t) => {
+  const database = new DatabaseSync(':memory:');
+  const session = database.createSession();
+  t.assert.throws(() => {
+    database.applyChangeset(null);
+  }, {
+    name: 'TypeError',
+    message: 'The "changeset" argument must be a Uint8Array.'
+  });
+
+  t.assert.throws(() => {
+    database.applyChangeset(session.changeset(), null);
+  }, {
+    name: 'TypeError',
+    message: 'The "options" argument must be an object.'
+  });
+
+  t.assert.throws(() => {
+    database.applyChangeset(session.changeset(), {
+      filter: null
+    }, null);
+  }, {
+    name: 'TypeError',
+    message: 'The "options.filter" argument must be a function.'
+  });
+
+  t.assert.throws(() => {
+    database.applyChangeset(session.changeset(), {
+      onConflict: null
+    }, null);
+  }, {
+    name: 'TypeError',
+    message: 'The "options.onConflict" argument must be a number.'
+  });
+});
+
+test('session.patchset()', (t) => {
+  const database = new DatabaseSync(':memory:');
+  database.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
+
+  database.exec("INSERT INTO data VALUES ('1', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.')");
+
+  const session = database.createSession();
+  database.exec("UPDATE data SET value = 'hi' WHERE key = 1");
+
+  const patchset = session.patchset();
+  const changeset = session.changeset();
+
+  t.assert.ok(patchset instanceof Uint8Array);
+  t.assert.ok(changeset instanceof Uint8Array);
+
+  t.assert.deepStrictEqual(patchset, session.patchset());
+  t.assert.deepStrictEqual(changeset, session.changeset());
+
+  t.assert.ok(
+    patchset.length < changeset.length,
+    'expected patchset to be smaller than changeset');
+});
+
+test('session.close() - using session after close throws exception', (t) => {
+  const database = new DatabaseSync(':memory:');
+  database.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
+
+  database.exec("INSERT INTO data VALUES ('1', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.')");
+
+  const session = database.createSession();
+  database.exec("UPDATE data SET value = 'hi' WHERE key = 1");
+  session.close();
+
+  database.exec("UPDATE data SET value = 'world' WHERE key = 1");
+  t.assert.throws(() => {
+    session.changeset();
+  }, {
+    name: 'Error',
+    message: 'session is not open'
+  });
+});
+
+test('session.close() - after closing database throws exception', (t) => {
+  const database = new DatabaseSync(':memory:');
+  database.exec('CREATE TABLE data(key INTEGER PRIMARY KEY, value TEXT)');
+
+  database.exec("INSERT INTO data VALUES ('1', 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.')");
+
+  const session = database.createSession();
+  database.close();
+
+  t.assert.throws(() => {
+    session.close();
+  }, {
+    name: 'Error',
+    message: 'database is not open'
+  });
+});
+
+test('session.close() - closing twice', (t) => {
+  const database = new DatabaseSync(':memory:');
+  const session = database.createSession();
+  session.close();
+
+  t.assert.throws(() => {
+    session.close();
+  }, {
+    name: 'Error',
+    message: 'session is not open'
+  });
+});

tools/doc/type-parser.mjs

@@ -199,6 +199,7 @@ const customTypesMap = {
 
   'repl.REPLServer': 'repl.html#class-replserver',
 
+  'Session': 'sqlite.html#class-session',
   'StatementSync': 'sqlite.html#class-statementsync',
 
   'Stream': 'stream.html#stream',