+
+/* Reads and returns the value of 'column' within 'row'. If an ongoing
+ * transaction has changed 'column''s value, the modified value is returned.
+ *
+ * The caller must not modify or free the returned value.
+ *
+ * Various kinds of changes can invalidate the returned value: writing to the
+ * same 'column' in 'row' (e.g. with ovsdb_idl_txn_write()), deleting 'row'
+ * (e.g. with ovsdb_idl_txn_delete()), or completing an ongoing transaction
+ * (e.g. with ovsdb_idl_txn_commit() or ovsdb_idl_txn_abort()). If the
+ * returned value is needed for a long time, it is best to make a copy of it
+ * with ovsdb_datum_clone(). */
+const struct ovsdb_datum *
+ovsdb_idl_read(const struct ovsdb_idl_row *row,
+ const struct ovsdb_idl_column *column)
+{
+ const struct ovsdb_idl_table_class *class;
+ size_t column_idx;
+
+ ovs_assert(!ovsdb_idl_row_is_synthetic(row));
+
+ class = row->table->class;
+ column_idx = column - class->columns;
+
+ ovs_assert(row->new != NULL);
+ ovs_assert(column_idx < class->n_columns);
+
+ if (row->written && bitmap_is_set(row->written, column_idx)) {
+ return &row->new[column_idx];
+ } else if (row->old) {
+ return &row->old[column_idx];
+ } else {
+ return ovsdb_datum_default(&column->type);
+ }
+}
+
+/* Same as ovsdb_idl_read(), except that it also asserts that 'column' has key
+ * type 'key_type' and value type 'value_type'. (Scalar and set types will
+ * have a value type of OVSDB_TYPE_VOID.)
+ *
+ * This is useful in code that "knows" that a particular column has a given
+ * type, so that it will abort if someone changes the column's type without
+ * updating the code that uses it. */
+const struct ovsdb_datum *
+ovsdb_idl_get(const struct ovsdb_idl_row *row,
+ const struct ovsdb_idl_column *column,
+ enum ovsdb_atomic_type key_type OVS_UNUSED,
+ enum ovsdb_atomic_type value_type OVS_UNUSED)
+{
+ ovs_assert(column->type.key.type == key_type);
+ ovs_assert(column->type.value.type == value_type);
+
+ return ovsdb_idl_read(row, column);
+}
+
+/* Returns false if 'row' was obtained from the IDL, true if it was initialized
+ * to all-zero-bits by some other entity. If 'row' was set up some other way
+ * then the return value is indeterminate. */
+bool
+ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row *row)
+{
+ return row->table == NULL;
+}
+\f
+/* Transactions. */
+
+static void ovsdb_idl_txn_complete(struct ovsdb_idl_txn *txn,
+ enum ovsdb_idl_txn_status);
+
+/* Returns a string representation of 'status'. The caller must not modify or
+ * free the returned string.
+ *
+ * The return value is probably useful only for debug log messages and unit
+ * tests. */
+const char *
+ovsdb_idl_txn_status_to_string(enum ovsdb_idl_txn_status status)
+{
+ switch (status) {
+ case TXN_UNCOMMITTED:
+ return "uncommitted";
+ case TXN_UNCHANGED:
+ return "unchanged";
+ case TXN_INCOMPLETE:
+ return "incomplete";
+ case TXN_ABORTED:
+ return "aborted";
+ case TXN_SUCCESS:
+ return "success";
+ case TXN_TRY_AGAIN:
+ return "try again";
+ case TXN_NOT_LOCKED:
+ return "not locked";
+ case TXN_ERROR:
+ return "error";
+ }
+ return "<unknown>";
+}
+
+/* Starts a new transaction on 'idl'. A given ovsdb_idl may only have a single
+ * active transaction at a time. See the large comment in ovsdb-idl.h for
+ * general information on transactions. */
+struct ovsdb_idl_txn *
+ovsdb_idl_txn_create(struct ovsdb_idl *idl)
+{
+ struct ovsdb_idl_txn *txn;
+
+ ovs_assert(!idl->txn);
+ idl->txn = txn = xmalloc(sizeof *txn);
+ txn->request_id = NULL;
+ txn->idl = idl;
+ hmap_init(&txn->txn_rows);
+ txn->status = TXN_UNCOMMITTED;
+ txn->error = NULL;
+ txn->dry_run = false;
+ ds_init(&txn->comment);
+
+ txn->inc_table = NULL;
+ txn->inc_column = NULL;
+
+ hmap_init(&txn->inserted_rows);
+
+ return txn;
+}
+
+/* Appends 's', which is treated as a printf()-type format string, to the
+ * comments that will be passed to the OVSDB server when 'txn' is committed.
+ * (The comment will be committed to the OVSDB log, which "ovsdb-tool
+ * show-log" can print in a relatively human-readable form.) */
+void
+ovsdb_idl_txn_add_comment(struct ovsdb_idl_txn *txn, const char *s, ...)
+{
+ va_list args;
+
+ if (txn->comment.length) {
+ ds_put_char(&txn->comment, '\n');
+ }
+
+ va_start(args, s);
+ ds_put_format_valist(&txn->comment, s, args);
+ va_end(args);
+}
+
+/* Marks 'txn' as a transaction that will not actually modify the database. In
+ * almost every way, the transaction is treated like other transactions. It
+ * must be committed or aborted like other transactions, it will be sent to the
+ * database server like other transactions, and so on. The only difference is
+ * that the operations sent to the database server will include, as the last
+ * step, an "abort" operation, so that any changes made by the transaction will
+ * not actually take effect. */
+void
+ovsdb_idl_txn_set_dry_run(struct ovsdb_idl_txn *txn)
+{
+ txn->dry_run = true;
+}
+
+/* Causes 'txn', when committed, to increment the value of 'column' within
+ * 'row' by 1. 'column' must have an integer type. After 'txn' commits
+ * successfully, the client may retrieve the final (incremented) value of
+ * 'column' with ovsdb_idl_txn_get_increment_new_value().
+ *
+ * The client could accomplish something similar with ovsdb_idl_read(),
+ * ovsdb_idl_txn_verify() and ovsdb_idl_txn_write(), or with ovsdb-idlc
+ * generated wrappers for these functions. However, ovsdb_idl_txn_increment()
+ * will never (by itself) fail because of a verify error.
+ *
+ * The intended use is for incrementing the "next_cfg" column in the
+ * Open_vSwitch table. */
+void
+ovsdb_idl_txn_increment(struct ovsdb_idl_txn *txn,
+ const struct ovsdb_idl_row *row,
+ const struct ovsdb_idl_column *column)
+{
+ ovs_assert(!txn->inc_table);
+ ovs_assert(column->type.key.type == OVSDB_TYPE_INTEGER);
+ ovs_assert(column->type.value.type == OVSDB_TYPE_VOID);
+
+ txn->inc_table = row->table->class->name;
+ txn->inc_column = column->name;
+ txn->inc_row = row->uuid;
+}
+
+/* Destroys 'txn' and frees all associated memory. If ovsdb_idl_txn_commit()
+ * has been called for 'txn' but the commit is still incomplete (that is, the
+ * last call returned TXN_INCOMPLETE) then the transaction may or may not still
+ * end up committing at the database server, but the client will not be able to
+ * get any further status information back. */
+void
+ovsdb_idl_txn_destroy(struct ovsdb_idl_txn *txn)
+{
+ struct ovsdb_idl_txn_insert *insert, *next;
+
+ json_destroy(txn->request_id);
+ if (txn->status == TXN_INCOMPLETE) {
+ hmap_remove(&txn->idl->outstanding_txns, &txn->hmap_node);
+ }
+ ovsdb_idl_txn_abort(txn);
+ ds_destroy(&txn->comment);
+ free(txn->error);
+ HMAP_FOR_EACH_SAFE (insert, next, hmap_node, &txn->inserted_rows) {
+ free(insert);
+ }
+ hmap_destroy(&txn->inserted_rows);
+ free(txn);
+}
+
+/* Causes poll_block() to wake up if 'txn' has completed committing. */
+void
+ovsdb_idl_txn_wait(const struct ovsdb_idl_txn *txn)
+{
+ if (txn->status != TXN_UNCOMMITTED && txn->status != TXN_INCOMPLETE) {
+ poll_immediate_wake();
+ }
+}
+
+static struct json *
+where_uuid_equals(const struct uuid *uuid)
+{
+ return
+ json_array_create_1(
+ json_array_create_3(
+ json_string_create("_uuid"),
+ json_string_create("=="),
+ json_array_create_2(
+ json_string_create("uuid"),
+ json_string_create_nocopy(
+ xasprintf(UUID_FMT, UUID_ARGS(uuid))))));
+}
+
+static char *
+uuid_name_from_uuid(const struct uuid *uuid)
+{
+ char *name;
+ char *p;
+
+ name = xasprintf("row"UUID_FMT, UUID_ARGS(uuid));
+ for (p = name; *p != '\0'; p++) {
+ if (*p == '-') {
+ *p = '_';
+ }
+ }
+
+ return name;
+}
+
+static const struct ovsdb_idl_row *
+ovsdb_idl_txn_get_row(const struct ovsdb_idl_txn *txn, const struct uuid *uuid)
+{
+ const struct ovsdb_idl_row *row;
+
+ HMAP_FOR_EACH_WITH_HASH (row, txn_node, uuid_hash(uuid), &txn->txn_rows) {
+ if (uuid_equals(&row->uuid, uuid)) {
+ return row;
+ }
+ }
+ return NULL;
+}
+
+/* XXX there must be a cleaner way to do this */
+static struct json *
+substitute_uuids(struct json *json, const struct ovsdb_idl_txn *txn)
+{
+ if (json->type == JSON_ARRAY) {
+ struct uuid uuid;
+ size_t i;
+
+ if (json->u.array.n == 2
+ && json->u.array.elems[0]->type == JSON_STRING
+ && json->u.array.elems[1]->type == JSON_STRING
+ && !strcmp(json->u.array.elems[0]->u.string, "uuid")
+ && uuid_from_string(&uuid, json->u.array.elems[1]->u.string)) {
+ const struct ovsdb_idl_row *row;
+
+ row = ovsdb_idl_txn_get_row(txn, &uuid);
+ if (row && !row->old && row->new) {
+ json_destroy(json);
+
+ return json_array_create_2(
+ json_string_create("named-uuid"),
+ json_string_create_nocopy(uuid_name_from_uuid(&uuid)));
+ }
+ }
+
+ for (i = 0; i < json->u.array.n; i++) {
+ json->u.array.elems[i] = substitute_uuids(json->u.array.elems[i],
+ txn);
+ }
+ } else if (json->type == JSON_OBJECT) {
+ struct shash_node *node;
+
+ SHASH_FOR_EACH (node, json_object(json)) {
+ node->data = substitute_uuids(node->data, txn);
+ }
+ }
+ return json;
+}
+
+static void
+ovsdb_idl_txn_disassemble(struct ovsdb_idl_txn *txn)
+{
+ struct ovsdb_idl_row *row, *next;
+
+ /* This must happen early. Otherwise, ovsdb_idl_row_parse() will call an
+ * ovsdb_idl_column's 'parse' function, which will call
+ * ovsdb_idl_get_row_arc(), which will seen that the IDL is in a
+ * transaction and fail to update the graph. */
+ txn->idl->txn = NULL;
+
+ HMAP_FOR_EACH_SAFE (row, next, txn_node, &txn->txn_rows) {
+ if (row->old) {
+ if (row->written) {
+ ovsdb_idl_row_unparse(row);
+ ovsdb_idl_row_clear_arcs(row, false);
+ ovsdb_idl_row_parse(row);
+ }
+ } else {
+ ovsdb_idl_row_unparse(row);
+ }
+ ovsdb_idl_row_clear_new(row);
+
+ free(row->prereqs);
+ row->prereqs = NULL;
+
+ free(row->written);
+ row->written = NULL;
+
+ hmap_remove(&txn->txn_rows, &row->txn_node);
+ hmap_node_nullify(&row->txn_node);
+ if (!row->old) {
+ hmap_remove(&row->table->rows, &row->hmap_node);
+ free(row);
+ }
+ }
+ hmap_destroy(&txn->txn_rows);
+ hmap_init(&txn->txn_rows);
+}
+
+/* Attempts to commit 'txn'. Returns the status of the commit operation, one
+ * of the following TXN_* constants:
+ *
+ * TXN_INCOMPLETE:
+ *
+ * The transaction is in progress, but not yet complete. The caller
+ * should call again later, after calling ovsdb_idl_run() to let the IDL
+ * do OVSDB protocol processing.
+ *
+ * TXN_UNCHANGED:
+ *
+ * The transaction is complete. (It didn't actually change the database,
+ * so the IDL didn't send any request to the database server.)
+ *
+ * TXN_ABORTED:
+ *
+ * The caller previously called ovsdb_idl_txn_abort().
+ *
+ * TXN_SUCCESS:
+ *
+ * The transaction was successful. The update made by the transaction
+ * (and possibly other changes made by other database clients) should
+ * already be visible in the IDL.
+ *
+ * TXN_TRY_AGAIN:
+ *
+ * The transaction failed for some transient reason, e.g. because a
+ * "verify" operation reported an inconsistency or due to a network
+ * problem. The caller should wait for a change to the database, then
+ * compose a new transaction, and commit the new transaction.
+ *
+ * Use the return value of ovsdb_idl_get_seqno() to wait for a change in
+ * the database. It is important to use its return value *before* the
+ * initial call to ovsdb_idl_txn_commit() as the baseline for this
+ * purpose, because the change that one should wait for can happen after
+ * the initial call but before the call that returns TXN_TRY_AGAIN, and
+ * using some other baseline value in that situation could cause an
+ * indefinite wait if the database rarely changes.
+ *
+ * TXN_NOT_LOCKED:
+ *
+ * The transaction failed because the IDL has been configured to require
+ * a database lock (with ovsdb_idl_set_lock()) but didn't get it yet or
+ * has already lost it.
+ *
+ * Committing a transaction rolls back all of the changes that it made to the
+ * IDL's copy of the database. If the transaction commits successfully, then
+ * the database server will send an update and, thus, the IDL will be updated
+ * with the committed changes. */
+enum ovsdb_idl_txn_status
+ovsdb_idl_txn_commit(struct ovsdb_idl_txn *txn)
+{
+ struct ovsdb_idl_row *row;
+ struct json *operations;
+ bool any_updates;
+
+ if (txn != txn->idl->txn) {
+ return txn->status;
+ }
+
+ /* If we need a lock but don't have it, give up quickly. */
+ if (txn->idl->lock_name && !ovsdb_idl_has_lock(txn->idl)) {
+ txn->status = TXN_NOT_LOCKED;
+ ovsdb_idl_txn_disassemble(txn);
+ return txn->status;
+ }
+
+ operations = json_array_create_1(
+ json_string_create(txn->idl->class->database));
+
+ /* Assert that we have the required lock (avoiding a race). */
+ if (txn->idl->lock_name) {
+ struct json *op = json_object_create();
+ json_array_add(operations, op);
+ json_object_put_string(op, "op", "assert");
+ json_object_put_string(op, "lock", txn->idl->lock_name);
+ }
+
+ /* Add prerequisites and declarations of new rows. */
+ HMAP_FOR_EACH (row, txn_node, &txn->txn_rows) {
+ /* XXX check that deleted rows exist even if no prereqs? */
+ if (row->prereqs) {
+ const struct ovsdb_idl_table_class *class = row->table->class;
+ size_t n_columns = class->n_columns;
+ struct json *op, *columns, *row_json;
+ size_t idx;
+
+ op = json_object_create();
+ json_array_add(operations, op);
+ json_object_put_string(op, "op", "wait");
+ json_object_put_string(op, "table", class->name);
+ json_object_put(op, "timeout", json_integer_create(0));
+ json_object_put(op, "where", where_uuid_equals(&row->uuid));
+ json_object_put_string(op, "until", "==");
+ columns = json_array_create_empty();
+ json_object_put(op, "columns", columns);
+ row_json = json_object_create();
+ json_object_put(op, "rows", json_array_create_1(row_json));
+
+ BITMAP_FOR_EACH_1 (idx, n_columns, row->prereqs) {
+ const struct ovsdb_idl_column *column = &class->columns[idx];
+ json_array_add(columns, json_string_create(column->name));
+ json_object_put(row_json, column->name,
+ ovsdb_datum_to_json(&row->old[idx],
+ &column->type));
+ }
+ }
+ }
+
+ /* Add updates. */
+ any_updates = false;
+ HMAP_FOR_EACH (row, txn_node, &txn->txn_rows) {
+ const struct ovsdb_idl_table_class *class = row->table->class;
+
+ if (!row->new) {
+ if (class->is_root) {
+ struct json *op = json_object_create();
+ json_object_put_string(op, "op", "delete");
+ json_object_put_string(op, "table", class->name);
+ json_object_put(op, "where", where_uuid_equals(&row->uuid));
+ json_array_add(operations, op);
+ any_updates = true;
+ } else {
+ /* Let ovsdb-server decide whether to really delete it. */
+ }
+ } else if (row->old != row->new) {
+ struct json *row_json;
+ struct json *op;
+ size_t idx;
+
+ op = json_object_create();
+ json_object_put_string(op, "op", row->old ? "update" : "insert");
+ json_object_put_string(op, "table", class->name);
+ if (row->old) {
+ json_object_put(op, "where", where_uuid_equals(&row->uuid));
+ } else {
+ struct ovsdb_idl_txn_insert *insert;
+
+ any_updates = true;
+
+ json_object_put(op, "uuid-name",
+ json_string_create_nocopy(
+ uuid_name_from_uuid(&row->uuid)));
+
+ insert = xmalloc(sizeof *insert);
+ insert->dummy = row->uuid;
+ insert->op_index = operations->u.array.n - 1;
+ uuid_zero(&insert->real);
+ hmap_insert(&txn->inserted_rows, &insert->hmap_node,
+ uuid_hash(&insert->dummy));
+ }
+ row_json = json_object_create();
+ json_object_put(op, "row", row_json);
+
+ if (row->written) {
+ BITMAP_FOR_EACH_1 (idx, class->n_columns, row->written) {
+ const struct ovsdb_idl_column *column =
+ &class->columns[idx];
+
+ if (row->old
+ || !ovsdb_datum_is_default(&row->new[idx],
+ &column->type)) {
+ json_object_put(row_json, column->name,
+ substitute_uuids(
+ ovsdb_datum_to_json(&row->new[idx],
+ &column->type),
+ txn));
+
+ /* If anything really changed, consider it an update.
+ * We can't suppress not-really-changed values earlier
+ * or transactions would become nonatomic (see the big
+ * comment inside ovsdb_idl_txn_write()). */
+ if (!any_updates && row->old &&
+ !ovsdb_datum_equals(&row->old[idx], &row->new[idx],
+ &column->type)) {
+ any_updates = true;
+ }
+ }
+ }
+ }
+
+ if (!row->old || !shash_is_empty(json_object(row_json))) {
+ json_array_add(operations, op);
+ } else {
+ json_destroy(op);
+ }
+ }
+ }
+
+ /* Add increment. */
+ if (txn->inc_table && any_updates) {
+ struct json *op;
+
+ txn->inc_index = operations->u.array.n - 1;
+
+ op = json_object_create();
+ json_object_put_string(op, "op", "mutate");
+ json_object_put_string(op, "table", txn->inc_table);
+ json_object_put(op, "where",
+ substitute_uuids(where_uuid_equals(&txn->inc_row),
+ txn));
+ json_object_put(op, "mutations",
+ json_array_create_1(
+ json_array_create_3(
+ json_string_create(txn->inc_column),
+ json_string_create("+="),
+ json_integer_create(1))));
+ json_array_add(operations, op);
+
+ op = json_object_create();
+ json_object_put_string(op, "op", "select");
+ json_object_put_string(op, "table", txn->inc_table);
+ json_object_put(op, "where",
+ substitute_uuids(where_uuid_equals(&txn->inc_row),
+ txn));
+ json_object_put(op, "columns",
+ json_array_create_1(json_string_create(
+ txn->inc_column)));
+ json_array_add(operations, op);
+ }
+
+ if (txn->comment.length) {
+ struct json *op = json_object_create();
+ json_object_put_string(op, "op", "comment");
+ json_object_put_string(op, "comment", ds_cstr(&txn->comment));
+ json_array_add(operations, op);
+ }
+
+ if (txn->dry_run) {
+ struct json *op = json_object_create();
+ json_object_put_string(op, "op", "abort");
+ json_array_add(operations, op);
+ }
+
+ if (!any_updates) {
+ txn->status = TXN_UNCHANGED;
+ json_destroy(operations);
+ } else if (!jsonrpc_session_send(
+ txn->idl->session,
+ jsonrpc_create_request(
+ "transact", operations, &txn->request_id))) {
+ hmap_insert(&txn->idl->outstanding_txns, &txn->hmap_node,
+ json_hash(txn->request_id, 0));
+ txn->status = TXN_INCOMPLETE;
+ } else {
+ txn->status = TXN_TRY_AGAIN;
+ }
+
+ ovsdb_idl_txn_disassemble(txn);
+ return txn->status;
+}
+
+/* Attempts to commit 'txn', blocking until the commit either succeeds or
+ * fails. Returns the final commit status, which may be any TXN_* value other
+ * than TXN_INCOMPLETE.
+ *
+ * This function calls ovsdb_idl_run() on 'txn''s IDL, so it may cause the
+ * return value of ovsdb_idl_get_seqno() to change. */
+enum ovsdb_idl_txn_status
+ovsdb_idl_txn_commit_block(struct ovsdb_idl_txn *txn)
+{
+ enum ovsdb_idl_txn_status status;
+
+ fatal_signal_run();
+ while ((status = ovsdb_idl_txn_commit(txn)) == TXN_INCOMPLETE) {
+ ovsdb_idl_run(txn->idl);
+ ovsdb_idl_wait(txn->idl);
+ ovsdb_idl_txn_wait(txn);
+ poll_block();
+ }
+ return status;
+}
+
+/* Returns the final (incremented) value of the column in 'txn' that was set to
+ * be incremented by ovsdb_idl_txn_increment(). 'txn' must have committed
+ * successfully. */
+int64_t
+ovsdb_idl_txn_get_increment_new_value(const struct ovsdb_idl_txn *txn)
+{
+ ovs_assert(txn->status == TXN_SUCCESS);
+ return txn->inc_new_value;
+}
+
+/* Aborts 'txn' without sending it to the database server. This is effective
+ * only if ovsdb_idl_txn_commit() has not yet been called for 'txn'.
+ * Otherwise, it has no effect.
+ *
+ * Aborting a transaction doesn't free its memory. Use
+ * ovsdb_idl_txn_destroy() to do that. */
+void
+ovsdb_idl_txn_abort(struct ovsdb_idl_txn *txn)
+{
+ ovsdb_idl_txn_disassemble(txn);
+ if (txn->status == TXN_UNCOMMITTED || txn->status == TXN_INCOMPLETE) {
+ txn->status = TXN_ABORTED;
+ }
+}
+
+/* Returns a string that reports the error status for 'txn'. The caller must
+ * not modify or free the returned string. A call to ovsdb_idl_txn_destroy()
+ * for 'txn' may free the returned string.
+ *
+ * The return value is ordinarily one of the strings that
+ * ovsdb_idl_txn_status_to_string() would return, but if the transaction failed
+ * due to an error reported by the database server, the return value is that
+ * error. */
+const char *
+ovsdb_idl_txn_get_error(const struct ovsdb_idl_txn *txn)
+{
+ if (txn->status != TXN_ERROR) {
+ return ovsdb_idl_txn_status_to_string(txn->status);
+ } else if (txn->error) {
+ return txn->error;
+ } else {
+ return "no error details available";
+ }
+}
+
+static void
+ovsdb_idl_txn_set_error_json(struct ovsdb_idl_txn *txn,
+ const struct json *json)
+{
+ if (txn->error == NULL) {
+ txn->error = json_to_string(json, JSSF_SORT);
+ }
+}
+
+/* For transaction 'txn' that completed successfully, finds and returns the
+ * permanent UUID that the database assigned to a newly inserted row, given the
+ * 'uuid' that ovsdb_idl_txn_insert() assigned locally to that row.
+ *
+ * Returns NULL if 'uuid' is not a UUID assigned by ovsdb_idl_txn_insert() or
+ * if it was assigned by that function and then deleted by
+ * ovsdb_idl_txn_delete() within the same transaction. (Rows that are inserted
+ * and then deleted within a single transaction are never sent to the database
+ * server, so it never assigns them a permanent UUID.) */
+const struct uuid *
+ovsdb_idl_txn_get_insert_uuid(const struct ovsdb_idl_txn *txn,
+ const struct uuid *uuid)
+{
+ const struct ovsdb_idl_txn_insert *insert;
+
+ ovs_assert(txn->status == TXN_SUCCESS || txn->status == TXN_UNCHANGED);
+ HMAP_FOR_EACH_IN_BUCKET (insert, hmap_node,
+ uuid_hash(uuid), &txn->inserted_rows) {
+ if (uuid_equals(uuid, &insert->dummy)) {
+ return &insert->real;
+ }
+ }
+ return NULL;
+}
+
+static void
+ovsdb_idl_txn_complete(struct ovsdb_idl_txn *txn,
+ enum ovsdb_idl_txn_status status)
+{
+ txn->status = status;
+ hmap_remove(&txn->idl->outstanding_txns, &txn->hmap_node);
+}
+
+/* Writes 'datum' to the specified 'column' in 'row_'. Updates both 'row_'
+ * itself and the structs derived from it (e.g. the "struct ovsrec_*", for
+ * ovs-vswitchd).
+ *
+ * 'datum' must have the correct type for its column. The IDL does not check
+ * that it meets schema constraints, but ovsdb-server will do so at commit time
+ * so it had better be correct.
+ *
+ * A transaction must be in progress. Replication of 'column' must not have
+ * been disabled (by calling ovsdb_idl_omit()).
+ *
+ * Usually this function is used indirectly through one of the "set" functions
+ * generated by ovsdb-idlc.
+ *
+ * Takes ownership of what 'datum' points to (and in some cases destroys that
+ * data before returning) but makes a copy of 'datum' itself. (Commonly
+ * 'datum' is on the caller's stack.) */
+static void
+ovsdb_idl_txn_write__(const struct ovsdb_idl_row *row_,
+ const struct ovsdb_idl_column *column,
+ struct ovsdb_datum *datum, bool owns_datum)
+{
+ struct ovsdb_idl_row *row = CONST_CAST(struct ovsdb_idl_row *, row_);
+ const struct ovsdb_idl_table_class *class;
+ size_t column_idx;
+ bool write_only;
+
+ if (ovsdb_idl_row_is_synthetic(row)) {
+ goto discard_datum;
+ }
+
+ class = row->table->class;
+ column_idx = column - class->columns;
+ write_only = row->table->modes[column_idx] == OVSDB_IDL_MONITOR;
+
+ ovs_assert(row->new != NULL);
+ ovs_assert(column_idx < class->n_columns);
+ ovs_assert(row->old == NULL ||
+ row->table->modes[column_idx] & OVSDB_IDL_MONITOR);
+
+ if (row->table->idl->verify_write_only && !write_only) {
+ VLOG_ERR("Bug: Attempt to write to a read/write column (%s:%s) when"
+ " explicitly configured not to.", class->name, column->name);
+ goto discard_datum;
+ }
+
+ /* If this is a write-only column and the datum being written is the same
+ * as the one already there, just skip the update entirely. This is worth
+ * optimizing because we have a lot of columns that get periodically
+ * refreshed into the database but don't actually change that often.
+ *
+ * We don't do this for read/write columns because that would break
+ * atomicity of transactions--some other client might have written a
+ * different value in that column since we read it. (But if a whole
+ * transaction only does writes of existing values, without making any real
+ * changes, we will drop the whole transaction later in
+ * ovsdb_idl_txn_commit().) */
+ if (write_only && ovsdb_datum_equals(ovsdb_idl_read(row, column),
+ datum, &column->type)) {
+ goto discard_datum;
+ }
+
+ if (hmap_node_is_null(&row->txn_node)) {
+ hmap_insert(&row->table->idl->txn->txn_rows, &row->txn_node,
+ uuid_hash(&row->uuid));
+ }
+ if (row->old == row->new) {
+ row->new = xmalloc(class->n_columns * sizeof *row->new);
+ }
+ if (!row->written) {
+ row->written = bitmap_allocate(class->n_columns);
+ }
+ if (bitmap_is_set(row->written, column_idx)) {
+ ovsdb_datum_destroy(&row->new[column_idx], &column->type);
+ } else {
+ bitmap_set1(row->written, column_idx);
+ }
+ if (owns_datum) {
+ row->new[column_idx] = *datum;
+ } else {
+ ovsdb_datum_clone(&row->new[column_idx], datum, &column->type);
+ }
+ (column->unparse)(row);
+ (column->parse)(row, &row->new[column_idx]);
+ return;
+
+discard_datum:
+ if (owns_datum) {
+ ovsdb_datum_destroy(datum, &column->type);
+ }
+}
+
+void
+ovsdb_idl_txn_write(const struct ovsdb_idl_row *row,
+ const struct ovsdb_idl_column *column,
+ struct ovsdb_datum *datum)
+{
+ ovsdb_idl_txn_write__(row, column, datum, true);
+}
+
+void
+ovsdb_idl_txn_write_clone(const struct ovsdb_idl_row *row,
+ const struct ovsdb_idl_column *column,
+ const struct ovsdb_datum *datum)
+{
+ ovsdb_idl_txn_write__(row, column,
+ CONST_CAST(struct ovsdb_datum *, datum), false);
+}
+
+/* Causes the original contents of 'column' in 'row_' to be verified as a
+ * prerequisite to completing the transaction. That is, if 'column' in 'row_'
+ * changed (or if 'row_' was deleted) between the time that the IDL originally
+ * read its contents and the time that the transaction commits, then the
+ * transaction aborts and ovsdb_idl_txn_commit() returns TXN_AGAIN_WAIT or
+ * TXN_AGAIN_NOW (depending on whether the database change has already been
+ * received).
+ *
+ * The intention is that, to ensure that no transaction commits based on dirty
+ * reads, an application should call ovsdb_idl_txn_verify() on each data item
+ * read as part of a read-modify-write operation.
+ *
+ * In some cases ovsdb_idl_txn_verify() reduces to a no-op, because the current
+ * value of 'column' is already known:
+ *
+ * - If 'row_' is a row created by the current transaction (returned by
+ * ovsdb_idl_txn_insert()).
+ *
+ * - If 'column' has already been modified (with ovsdb_idl_txn_write())
+ * within the current transaction.
+ *
+ * Because of the latter property, always call ovsdb_idl_txn_verify() *before*
+ * ovsdb_idl_txn_write() for a given read-modify-write.
+ *
+ * A transaction must be in progress.
+ *
+ * Usually this function is used indirectly through one of the "verify"
+ * functions generated by ovsdb-idlc. */
+void
+ovsdb_idl_txn_verify(const struct ovsdb_idl_row *row_,
+ const struct ovsdb_idl_column *column)
+{
+ struct ovsdb_idl_row *row = CONST_CAST(struct ovsdb_idl_row *, row_);
+ const struct ovsdb_idl_table_class *class;
+ size_t column_idx;
+
+ if (ovsdb_idl_row_is_synthetic(row)) {
+ return;
+ }
+
+ class = row->table->class;
+ column_idx = column - class->columns;
+
+ ovs_assert(row->new != NULL);
+ ovs_assert(row->old == NULL ||
+ row->table->modes[column_idx] & OVSDB_IDL_MONITOR);
+ if (!row->old
+ || (row->written && bitmap_is_set(row->written, column_idx))) {
+ return;
+ }
+
+ if (hmap_node_is_null(&row->txn_node)) {
+ hmap_insert(&row->table->idl->txn->txn_rows, &row->txn_node,
+ uuid_hash(&row->uuid));
+ }
+ if (!row->prereqs) {
+ row->prereqs = bitmap_allocate(class->n_columns);
+ }
+ bitmap_set1(row->prereqs, column_idx);
+}
+
+/* Deletes 'row_' from its table. May free 'row_', so it must not be
+ * accessed afterward.
+ *
+ * A transaction must be in progress.
+ *
+ * Usually this function is used indirectly through one of the "delete"
+ * functions generated by ovsdb-idlc. */
+void
+ovsdb_idl_txn_delete(const struct ovsdb_idl_row *row_)
+{
+ struct ovsdb_idl_row *row = CONST_CAST(struct ovsdb_idl_row *, row_);
+
+ if (ovsdb_idl_row_is_synthetic(row)) {
+ return;
+ }
+
+ ovs_assert(row->new != NULL);
+ if (!row->old) {
+ ovsdb_idl_row_unparse(row);
+ ovsdb_idl_row_clear_new(row);
+ ovs_assert(!row->prereqs);
+ hmap_remove(&row->table->rows, &row->hmap_node);
+ hmap_remove(&row->table->idl->txn->txn_rows, &row->txn_node);
+ free(row);
+ return;
+ }
+ if (hmap_node_is_null(&row->txn_node)) {
+ hmap_insert(&row->table->idl->txn->txn_rows, &row->txn_node,
+ uuid_hash(&row->uuid));
+ }
+ ovsdb_idl_row_clear_new(row);
+ row->new = NULL;
+}
+
+/* Inserts and returns a new row in the table with the specified 'class' in the
+ * database with open transaction 'txn'.
+ *
+ * The new row is assigned a provisional UUID. If 'uuid' is null then one is
+ * randomly generated; otherwise 'uuid' should specify a randomly generated
+ * UUID not otherwise in use. ovsdb-server will assign a different UUID when
+ * 'txn' is committed, but the IDL will replace any uses of the provisional
+ * UUID in the data to be to be committed by the UUID assigned by
+ * ovsdb-server.
+ *
+ * Usually this function is used indirectly through one of the "insert"
+ * functions generated by ovsdb-idlc. */
+const struct ovsdb_idl_row *
+ovsdb_idl_txn_insert(struct ovsdb_idl_txn *txn,
+ const struct ovsdb_idl_table_class *class,
+ const struct uuid *uuid)
+{
+ struct ovsdb_idl_row *row = ovsdb_idl_row_create__(class);
+
+ if (uuid) {
+ ovs_assert(!ovsdb_idl_txn_get_row(txn, uuid));
+ row->uuid = *uuid;
+ } else {
+ uuid_generate(&row->uuid);
+ }
+
+ row->table = ovsdb_idl_table_from_class(txn->idl, class);
+ row->new = xmalloc(class->n_columns * sizeof *row->new);
+ hmap_insert(&row->table->rows, &row->hmap_node, uuid_hash(&row->uuid));
+ hmap_insert(&txn->txn_rows, &row->txn_node, uuid_hash(&row->uuid));
+ return row;
+}
+
+static void
+ovsdb_idl_txn_abort_all(struct ovsdb_idl *idl)
+{
+ struct ovsdb_idl_txn *txn;
+
+ HMAP_FOR_EACH (txn, hmap_node, &idl->outstanding_txns) {
+ ovsdb_idl_txn_complete(txn, TXN_TRY_AGAIN);
+ }
+}
+
+static struct ovsdb_idl_txn *
+ovsdb_idl_txn_find(struct ovsdb_idl *idl, const struct json *id)
+{
+ struct ovsdb_idl_txn *txn;
+
+ HMAP_FOR_EACH_WITH_HASH (txn, hmap_node,
+ json_hash(id, 0), &idl->outstanding_txns) {
+ if (json_equal(id, txn->request_id)) {
+ return txn;
+ }
+ }
+ return NULL;
+}
+
+static bool
+check_json_type(const struct json *json, enum json_type type, const char *name)
+{
+ if (!json) {
+ VLOG_WARN_RL(&syntax_rl, "%s is missing", name);
+ return false;
+ } else if (json->type != type) {
+ VLOG_WARN_RL(&syntax_rl, "%s is %s instead of %s",
+ name, json_type_to_string(json->type),
+ json_type_to_string(type));
+ return false;
+ } else {
+ return true;
+ }
+}
+
+static bool
+ovsdb_idl_txn_process_inc_reply(struct ovsdb_idl_txn *txn,
+ const struct json_array *results)
+{
+ struct json *count, *rows, *row, *column;
+ struct shash *mutate, *select;
+
+ if (txn->inc_index + 2 > results->n) {
+ VLOG_WARN_RL(&syntax_rl, "reply does not contain enough operations "
+ "for increment (has %"PRIuSIZE", needs %u)",
+ results->n, txn->inc_index + 2);
+ return false;
+ }
+
+ /* We know that this is a JSON object because the loop in
+ * ovsdb_idl_txn_process_reply() checked. */
+ mutate = json_object(results->elems[txn->inc_index]);
+ count = shash_find_data(mutate, "count");
+ if (!check_json_type(count, JSON_INTEGER, "\"mutate\" reply \"count\"")) {
+ return false;
+ }
+ if (count->u.integer != 1) {
+ VLOG_WARN_RL(&syntax_rl,
+ "\"mutate\" reply \"count\" is %lld instead of 1",
+ count->u.integer);
+ return false;
+ }
+
+ select = json_object(results->elems[txn->inc_index + 1]);
+ rows = shash_find_data(select, "rows");
+ if (!check_json_type(rows, JSON_ARRAY, "\"select\" reply \"rows\"")) {
+ return false;
+ }
+ if (rows->u.array.n != 1) {
+ VLOG_WARN_RL(&syntax_rl, "\"select\" reply \"rows\" has %"PRIuSIZE" elements "
+ "instead of 1",
+ rows->u.array.n);
+ return false;
+ }
+ row = rows->u.array.elems[0];
+ if (!check_json_type(row, JSON_OBJECT, "\"select\" reply row")) {
+ return false;
+ }
+ column = shash_find_data(json_object(row), txn->inc_column);
+ if (!check_json_type(column, JSON_INTEGER,
+ "\"select\" reply inc column")) {
+ return false;
+ }
+ txn->inc_new_value = column->u.integer;
+ return true;
+}
+
+static bool
+ovsdb_idl_txn_process_insert_reply(struct ovsdb_idl_txn_insert *insert,
+ const struct json_array *results)
+{
+ static const struct ovsdb_base_type uuid_type = OVSDB_BASE_UUID_INIT;
+ struct ovsdb_error *error;
+ struct json *json_uuid;
+ union ovsdb_atom uuid;
+ struct shash *reply;
+
+ if (insert->op_index >= results->n) {
+ VLOG_WARN_RL(&syntax_rl, "reply does not contain enough operations "
+ "for insert (has %"PRIuSIZE", needs %u)",
+ results->n, insert->op_index);
+ return false;
+ }
+
+ /* We know that this is a JSON object because the loop in
+ * ovsdb_idl_txn_process_reply() checked. */
+ reply = json_object(results->elems[insert->op_index]);
+ json_uuid = shash_find_data(reply, "uuid");
+ if (!check_json_type(json_uuid, JSON_ARRAY, "\"insert\" reply \"uuid\"")) {
+ return false;
+ }
+
+ error = ovsdb_atom_from_json(&uuid, &uuid_type, json_uuid, NULL);
+ if (error) {
+ char *s = ovsdb_error_to_string(error);
+ VLOG_WARN_RL(&syntax_rl, "\"insert\" reply \"uuid\" is not a JSON "
+ "UUID: %s", s);
+ free(s);
+ ovsdb_error_destroy(error);
+ return false;
+ }
+
+ insert->real = uuid.uuid;
+
+ return true;
+}
+
+static bool
+ovsdb_idl_txn_process_reply(struct ovsdb_idl *idl,
+ const struct jsonrpc_msg *msg)
+{
+ struct ovsdb_idl_txn *txn;
+ enum ovsdb_idl_txn_status status;
+
+ txn = ovsdb_idl_txn_find(idl, msg->id);
+ if (!txn) {
+ return false;
+ }
+
+ if (msg->type == JSONRPC_ERROR) {
+ status = TXN_ERROR;
+ } else if (msg->result->type != JSON_ARRAY) {
+ VLOG_WARN_RL(&syntax_rl, "reply to \"transact\" is not JSON array");
+ status = TXN_ERROR;
+ } else {
+ struct json_array *ops = &msg->result->u.array;
+ int hard_errors = 0;
+ int soft_errors = 0;
+ int lock_errors = 0;
+ size_t i;
+
+ for (i = 0; i < ops->n; i++) {
+ struct json *op = ops->elems[i];
+
+ if (op->type == JSON_NULL) {
+ /* This isn't an error in itself but indicates that some prior
+ * operation failed, so make sure that we know about it. */
+ soft_errors++;
+ } else if (op->type == JSON_OBJECT) {
+ struct json *error;
+
+ error = shash_find_data(json_object(op), "error");
+ if (error) {
+ if (error->type == JSON_STRING) {
+ if (!strcmp(error->u.string, "timed out")) {
+ soft_errors++;
+ } else if (!strcmp(error->u.string, "not owner")) {
+ lock_errors++;
+ } else if (strcmp(error->u.string, "aborted")) {
+ hard_errors++;
+ ovsdb_idl_txn_set_error_json(txn, op);
+ }
+ } else {
+ hard_errors++;
+ ovsdb_idl_txn_set_error_json(txn, op);
+ VLOG_WARN_RL(&syntax_rl,
+ "\"error\" in reply is not JSON string");
+ }
+ }
+ } else {
+ hard_errors++;
+ ovsdb_idl_txn_set_error_json(txn, op);
+ VLOG_WARN_RL(&syntax_rl,
+ "operation reply is not JSON null or object");
+ }
+ }
+
+ if (!soft_errors && !hard_errors && !lock_errors) {
+ struct ovsdb_idl_txn_insert *insert;
+
+ if (txn->inc_table && !ovsdb_idl_txn_process_inc_reply(txn, ops)) {
+ hard_errors++;
+ }
+
+ HMAP_FOR_EACH (insert, hmap_node, &txn->inserted_rows) {
+ if (!ovsdb_idl_txn_process_insert_reply(insert, ops)) {
+ hard_errors++;
+ }
+ }
+ }
+
+ status = (hard_errors ? TXN_ERROR
+ : lock_errors ? TXN_NOT_LOCKED
+ : soft_errors ? TXN_TRY_AGAIN
+ : TXN_SUCCESS);
+ }
+
+ ovsdb_idl_txn_complete(txn, status);
+ return true;
+}
+
+/* Returns the transaction currently active for 'row''s IDL. A transaction
+ * must currently be active. */
+struct ovsdb_idl_txn *
+ovsdb_idl_txn_get(const struct ovsdb_idl_row *row)
+{
+ struct ovsdb_idl_txn *txn = row->table->idl->txn;
+ ovs_assert(txn != NULL);
+ return txn;
+}
+
+/* Returns the IDL on which 'txn' acts. */
+struct ovsdb_idl *
+ovsdb_idl_txn_get_idl (struct ovsdb_idl_txn *txn)
+{
+ return txn->idl;
+}
+\f
+/* If 'lock_name' is nonnull, configures 'idl' to obtain the named lock from
+ * the database server and to avoid modifying the database when the lock cannot
+ * be acquired (that is, when another client has the same lock).
+ *
+ * If 'lock_name' is NULL, drops the locking requirement and releases the
+ * lock. */
+void
+ovsdb_idl_set_lock(struct ovsdb_idl *idl, const char *lock_name)
+{
+ ovs_assert(!idl->txn);
+ ovs_assert(hmap_is_empty(&idl->outstanding_txns));
+
+ if (idl->lock_name && (!lock_name || strcmp(lock_name, idl->lock_name))) {
+ /* Release previous lock. */
+ ovsdb_idl_send_unlock_request(idl);
+ free(idl->lock_name);
+ idl->lock_name = NULL;
+ idl->is_lock_contended = false;
+ }
+
+ if (lock_name && !idl->lock_name) {
+ /* Acquire new lock. */
+ idl->lock_name = xstrdup(lock_name);
+ ovsdb_idl_send_lock_request(idl);
+ }
+}
+
+/* Returns true if 'idl' is configured to obtain a lock and owns that lock.
+ *
+ * Locking and unlocking happens asynchronously from the database client's
+ * point of view, so the information is only useful for optimization (e.g. if
+ * the client doesn't have the lock then there's no point in trying to write to
+ * the database). */
+bool
+ovsdb_idl_has_lock(const struct ovsdb_idl *idl)
+{
+ return idl->has_lock;
+}
+
+/* Returns true if 'idl' is configured to obtain a lock but the database server
+ * has indicated that some other client already owns the requested lock. */
+bool
+ovsdb_idl_is_lock_contended(const struct ovsdb_idl *idl)
+{
+ return idl->is_lock_contended;
+}
+
+static void
+ovsdb_idl_update_has_lock(struct ovsdb_idl *idl, bool new_has_lock)
+{
+ if (new_has_lock && !idl->has_lock) {
+ if (!idl->monitor_request_id) {
+ idl->change_seqno++;
+ } else {
+ /* We're waiting for a monitor reply, so don't signal that the
+ * database changed. The monitor reply will increment change_seqno
+ * anyhow. */
+ }
+ idl->is_lock_contended = false;
+ }
+ idl->has_lock = new_has_lock;
+}
+
+static void
+ovsdb_idl_send_lock_request__(struct ovsdb_idl *idl, const char *method,
+ struct json **idp)
+{
+ ovsdb_idl_update_has_lock(idl, false);
+
+ json_destroy(idl->lock_request_id);
+ idl->lock_request_id = NULL;
+
+ if (jsonrpc_session_is_connected(idl->session)) {
+ struct json *params;
+
+ params = json_array_create_1(json_string_create(idl->lock_name));
+ jsonrpc_session_send(idl->session,
+ jsonrpc_create_request(method, params, idp));
+ }
+}
+
+static void
+ovsdb_idl_send_lock_request(struct ovsdb_idl *idl)
+{
+ ovsdb_idl_send_lock_request__(idl, "lock", &idl->lock_request_id);
+}
+
+static void
+ovsdb_idl_send_unlock_request(struct ovsdb_idl *idl)
+{
+ ovsdb_idl_send_lock_request__(idl, "unlock", NULL);
+}
+
+static void
+ovsdb_idl_parse_lock_reply(struct ovsdb_idl *idl, const struct json *result)
+{
+ bool got_lock;
+
+ json_destroy(idl->lock_request_id);
+ idl->lock_request_id = NULL;
+
+ if (result->type == JSON_OBJECT) {
+ const struct json *locked;
+
+ locked = shash_find_data(json_object(result), "locked");
+ got_lock = locked && locked->type == JSON_TRUE;
+ } else {
+ got_lock = false;
+ }
+
+ ovsdb_idl_update_has_lock(idl, got_lock);
+ if (!got_lock) {
+ idl->is_lock_contended = true;
+ }
+}
+
+static void
+ovsdb_idl_parse_lock_notify(struct ovsdb_idl *idl,
+ const struct json *params,
+ bool new_has_lock)
+{
+ if (idl->lock_name
+ && params->type == JSON_ARRAY
+ && json_array(params)->n > 0
+ && json_array(params)->elems[0]->type == JSON_STRING) {
+ const char *lock_name = json_string(json_array(params)->elems[0]);
+
+ if (!strcmp(idl->lock_name, lock_name)) {
+ ovsdb_idl_update_has_lock(idl, new_has_lock);
+ if (!new_has_lock) {
+ idl->is_lock_contended = true;
+ }
+ }
+ }
+}