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Diffstat (limited to 'src/libtracker-data/tracker-sparql-query.vala')
| -rw-r--r-- | src/libtracker-data/tracker-sparql-query.vala | 1102 |
1 files changed, 0 insertions, 1102 deletions
diff --git a/src/libtracker-data/tracker-sparql-query.vala b/src/libtracker-data/tracker-sparql-query.vala deleted file mode 100644 index 54ce57003..000000000 --- a/src/libtracker-data/tracker-sparql-query.vala +++ /dev/null @@ -1,1102 +0,0 @@ -/* - * Copyright (C) 2008-2010, Nokia - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the - * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, - * Boston, MA 02110-1301, USA. - */ - -namespace Tracker.Sparql { - enum VariableState { - NONE, - BOUND, - OPTIONAL - } - - enum UpdateType { - DELETE, - INSERT, - UPDATE - } - - // Represents a SQL table - class DataTable : Object { - public string sql_db_tablename; // as in db schema - public string sql_query_tablename; // temp. name, generated - public PredicateVariable predicate_variable; - } - - abstract class DataBinding : Object { - public PropertyType data_type; - public DataTable table; - public string sql_db_column_name; - public string sql_expression { - get { - if (this._sql_expression == null && table != null) { - this._sql_expression = "\"%s\".\"%s\"".printf (table.sql_query_tablename, sql_db_column_name); - } - return this._sql_expression; - } - set { - this._sql_expression = value; - } - } - string? _sql_expression; - public string get_extra_sql_expression (string suffix) { - return "\"%s\".\"%s:%s\"".printf (table.sql_query_tablename, sql_db_column_name, suffix); - } - } - - // Represents a mapping of a SPARQL literal to a SQL table and column - class LiteralBinding : DataBinding { - public bool is_fts_match; - public string literal; - } - - // Represents a mapping of a SPARQL variable to a SQL table and column - class VariableBinding : DataBinding { - public weak Variable variable; - // Specified whether SQL column may contain NULL entries - public bool maybe_null; - public bool in_simple_optional; - public Class? type; - } - - class VariableBindingList : Object { - public List<VariableBinding> list; - } - - class Variable : Object { - public string name { get; private set; } - public int index { get; private set; } - public string sql_expression { get; private set; } - public VariableBinding binding; - string sql_identifier; - - public Variable (string name, int index) { - this.name = name; - this.index = index; - this.sql_identifier = "%d_u".printf (index); - this.sql_expression = "\"%s\"".printf (sql_identifier); - } - - public string get_extra_sql_expression (string suffix) { - return "\"%s:%s\"".printf (sql_identifier, suffix); - } - - public static bool equal (Variable a, Variable b) { - return a.index == b.index; - } - - public static uint hash (Variable variable) { - return (uint) variable.index; - } - } - - class Context { - public weak Query query; - - public Context? parent_context; - // All SPARQL variables within a subgraph pattern (used by UNION) - // value is VariableState - public HashTable<Variable,int> var_set; - - public HashTable<string,Variable> var_map; - // All selected SPARQL variables (used by compositional subqueries) - public HashTable<Variable,int> select_var_set; - - // Variables used as predicates - public HashTable<Variable,PredicateVariable> predicate_variable_map; - - public bool scalar_subquery; - public bool need_binding_expression; - - public Context (Query query, Context? parent_context = null) { - this.query = query; - this.parent_context = parent_context; - this.var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null); - - if (parent_context == null) { - select_var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null); - var_map = new HashTable<string,Variable>.full (str_hash, str_equal, g_free, g_object_unref); - predicate_variable_map = new HashTable<Variable,PredicateVariable>.full (Variable.hash, Variable.equal, g_object_unref, g_object_unref); - } else { - select_var_set = parent_context.select_var_set; - var_map = parent_context.var_map; - predicate_variable_map = parent_context.predicate_variable_map; - } - } - - public Context.subquery (Query query, Context parent_context) { - this.query = query; - this.parent_context = parent_context; - this.var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null); - - select_var_set = new HashTable<Variable,int>.full (Variable.hash, Variable.equal, g_object_unref, null); - var_map = parent_context.var_map; - predicate_variable_map = new HashTable<Variable,PredicateVariable>.full (Variable.hash, Variable.equal, g_object_unref, g_object_unref); - scalar_subquery = true; - } - - internal unowned Variable get_variable (string name) { - unowned Variable result = this.var_map.lookup (name); - if (result == null) { - var variable = new Variable (name, ++query.last_var_index); - this.var_map.insert (name, variable); - - result = variable; - } - return result; - } - } - - class SelectContext : Context { - public PropertyType type; - public PropertyType[] types = {}; - public string[] variable_names = {}; - - public SelectContext (Query query, Context? parent_context = null) { - base (query, parent_context); - } - - public SelectContext.subquery (Query query, Context parent_context) { - base.subquery (query, parent_context); - } - } - - class Solution { - public HashTable<string,int?> hash; - public GenericArray<string> values; - public int solution_index; - - public Solution () { - this.hash = new HashTable<string,int?> (str_hash, str_equal); - this.values = new GenericArray<string> (); - } - - public string? lookup (string variable_name) { - int? variable_index = hash.get (variable_name); - if (variable_index == null) { - return null; - } - return values[solution_index * hash.size () + variable_index]; - } - } -} - -public class Tracker.Sparql.Query : Object { - SparqlScanner scanner; - - // token buffer - TokenInfo[] tokens; - // index of current token in buffer - int index; - // number of tokens in buffer - int size; - - const int BUFFER_SIZE = 32; - - struct TokenInfo { - public SparqlTokenType type; - public SourceLocation begin; - public SourceLocation end; - } - - const string FN_NS = "http://www.w3.org/2005/xpath-functions#"; - - string query_string; - bool update_extensions; - - internal Expression expression; - internal Pattern pattern; - - string current_graph; - string current_subject; - bool current_subject_is_var; - string current_predicate; - bool current_predicate_is_var; - - // SILENT => ignore (non-syntax) errors - bool silent; - - HashTable<string,string> prefix_map; - - // All SPARQL literals - internal List<LiteralBinding> bindings; - - internal Context context; - - int bnodeid = 0; - // base UUID used for blank nodes - uchar[] base_uuid; - HashTable<string,string> blank_nodes; - - public Data.Manager manager; - - // Keep track of used SQL identifiers for SPARQL variables - public int last_var_index; - - public bool no_cache { get; set; } - - public Query (Data.Manager manager, string query) { - no_cache = false; /* Start with false, expression sets it */ - tokens = new TokenInfo[BUFFER_SIZE]; - prefix_map = new HashTable<string,string>.full (str_hash, str_equal, g_free, g_free); - - base_uuid = new uchar[16]; - uuid_generate (base_uuid); - - this.query_string = query; - this.manager = manager; - - expression = new Expression (this); - pattern = new Pattern (this); - } - - public Query.update (Data.Manager manager, string query) { - this (manager, query); - this.update_extensions = true; - } - - string get_uuid_for_name (uchar[] base_uuid, string name) { - var checksum = new Checksum (ChecksumType.SHA1); - // base UUID, unique per file - checksum.update (base_uuid, 16); - - // node ID - checksum.update ((uchar[]) name, -1); - - string sha1 = checksum.get_string (); - - // generate name based uuid - return "urn:uuid:%.8s-%.4s-%.4s-%.4s-%.12s".printf ( - sha1, sha1.substring (8), sha1.substring (12), sha1.substring (16), sha1.substring (20)); - } - - internal string generate_bnodeid (string? user_bnodeid) { - // user_bnodeid is NULL for anonymous nodes - if (user_bnodeid == null) { - return ":%d".printf (++bnodeid); - } else { - string uri = null; - - if (blank_nodes != null) { - uri = blank_nodes.lookup (user_bnodeid); - if (uri != null) { - return uri; - } - } - - uri = get_uuid_for_name (base_uuid, user_bnodeid); - - if (blank_nodes != null) { - var iface = manager.get_db_interface (); - while (Data.query_resource_id (manager, iface, uri) > 0) { - // uri collision, generate new UUID - uchar[] new_base_uuid = new uchar[16]; - uuid_generate (new_base_uuid); - uri = get_uuid_for_name (new_base_uuid, user_bnodeid); - } - - blank_nodes.insert (user_bnodeid, uri); - } - - return uri; - } - } - - internal bool next () throws Sparql.Error { - index = (index + 1) % BUFFER_SIZE; - size--; - if (size <= 0) { - SourceLocation begin, end; - SparqlTokenType type = scanner.read_token (out begin, out end); - tokens[index].type = type; - tokens[index].begin = begin; - tokens[index].end = end; - size = 1; - } - return (tokens[index].type != SparqlTokenType.EOF); - } - - internal SparqlTokenType current () { - return tokens[index].type; - } - - internal SparqlTokenType last () { - int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE; - return tokens[last_index].type; - } - - internal bool accept (SparqlTokenType type) throws Sparql.Error { - if (current () == type) { - next (); - return true; - } - return false; - } - - internal void optional (SparqlTokenType type) throws Sparql.Error { - if (current () == type) - next (); - } - - internal Sparql.Error get_error (string msg) { - return new Sparql.Error.PARSE ("%d.%d: syntax error, %s".printf (tokens[index].begin.line, tokens[index].begin.column, msg)); - } - - internal Sparql.Error get_internal_error (string msg) { - return new Sparql.Error.INTERNAL ("%d.%d: %s".printf (tokens[index].begin.line, tokens[index].begin.column, msg)); - } - - internal bool expect (SparqlTokenType type) throws Sparql.Error { - if (accept (type)) { - return true; - } - - throw get_error ("expected %s".printf (type.to_string ())); - } - - internal SourceLocation get_location () { - return tokens[index].begin; - } - - internal void set_location (SourceLocation location) { - scanner.seek (location); - size = 0; - index = 0; - try { - next (); - } catch (Sparql.Error e) { - // this should never happen as this is the second time we scan this token - critical ("internal error: next in set_location failed"); - } - } - - internal string get_last_string (int strip = 0) { - int last_index = (index + BUFFER_SIZE - 1) % BUFFER_SIZE; - return ((string) (tokens[last_index].begin.pos + strip)).substring (0, (int) (tokens[last_index].end.pos - tokens[last_index].begin.pos - 2 * strip)); - } - - private void parse_prologue () throws Sparql.Error { - if (accept (SparqlTokenType.BASE)) { - expect (SparqlTokenType.IRI_REF); - } - while (accept (SparqlTokenType.PREFIX)) { - string ns = ""; - if (accept (SparqlTokenType.PN_PREFIX)) { - ns = get_last_string (); - } - expect (SparqlTokenType.COLON); - expect (SparqlTokenType.IRI_REF); - string uri = get_last_string (1); - prefix_map.insert (ns, uri); - } - } - - private void prepare_execute () throws DBInterfaceError, Sparql.Error, DateError { - assert (!update_extensions); - - scanner = new SparqlScanner ((char*) query_string, (long) query_string.length); - next (); - - // declare fn prefix for XPath functions - prefix_map.insert ("fn", FN_NS); - var ontologies = manager.get_ontologies (); - - foreach (Namespace ns in ontologies.get_namespaces ()) { - if (ns.prefix == null) { - critical ("Namespace does not specify a prefix: %s", ns.uri); - continue; - } - prefix_map.insert (ns.prefix, ns.uri); - } - - parse_prologue (); - } - - - public DBCursor? execute_cursor () throws DBInterfaceError, Sparql.Error, DateError { - - prepare_execute (); - - switch (current ()) { - case SparqlTokenType.SELECT: - return execute_select_cursor (); - case SparqlTokenType.CONSTRUCT: - throw get_internal_error ("CONSTRUCT is not supported"); - case SparqlTokenType.DESCRIBE: - throw get_internal_error ("DESCRIBE is not supported"); - case SparqlTokenType.ASK: - return execute_ask_cursor (); - case SparqlTokenType.INSERT: - case SparqlTokenType.DELETE: - case SparqlTokenType.DROP: - throw get_error ("INSERT and DELETE are not supported in query mode"); - default: - throw get_error ("expected SELECT or ASK"); - } - } - - public Variant? execute_update (bool blank) throws GLib.Error { - Variant result = null; - assert (update_extensions); - - scanner = new SparqlScanner ((char*) query_string, (long) query_string.length); - next (); - - // declare fn prefix for XPath functions - prefix_map.insert ("fn", FN_NS); - var ontologies = manager.get_ontologies (); - - foreach (Namespace ns in ontologies.get_namespaces ()) { - if (ns.prefix == null) { - critical ("Namespace does not specify a prefix: %s", ns.uri); - continue; - } - prefix_map.insert (ns.prefix, ns.uri); - } - - parse_prologue (); - - // SPARQL update supports multiple operations in a single query - VariantBuilder? ublank_nodes = null; - - if (blank) { - ublank_nodes = new VariantBuilder ((VariantType) "aaa{ss}"); - } - - while (current () != SparqlTokenType.EOF) { - switch (current ()) { - case SparqlTokenType.WITH: - case SparqlTokenType.INSERT: - case SparqlTokenType.DELETE: - if (blank) { - ublank_nodes.open ((VariantType) "aa{ss}"); - execute_insert_delete (ublank_nodes); - ublank_nodes.close (); - } else { - execute_insert_delete (null); - } - break; - case SparqlTokenType.DROP: - throw get_internal_error ("DROP GRAPH is not supported"); - case SparqlTokenType.SELECT: - case SparqlTokenType.CONSTRUCT: - case SparqlTokenType.DESCRIBE: - case SparqlTokenType.ASK: - throw get_error ("SELECT, CONSTRUCT, DESCRIBE, and ASK are not supported in update mode"); - default: - throw get_error ("expected INSERT or DELETE"); - } - - // semicolon is used to separate multiple operations in the current SPARQL Update draft - // keep it optional for now to reatin backward compatibility - optional (SparqlTokenType.SEMICOLON); - } - - if (blank) { - result = ublank_nodes.end (); - } - - return result; - } - - private DBStatement prepare_for_exec (DBInterface iface, string sql) throws DBInterfaceError, Sparql.Error, DateError { - var stmt = iface.create_statement (no_cache ? DBStatementCacheType.NONE : DBStatementCacheType.SELECT, "%s", sql); - - // set literals specified in query - int i = 0; - foreach (LiteralBinding binding in bindings) { - if (binding.data_type == PropertyType.BOOLEAN) { - if (binding.literal == "true" || binding.literal == "1") { - stmt.bind_int (i, 1); - } else if (binding.literal == "false" || binding.literal == "0") { - stmt.bind_int (i, 0); - } else { - throw new Sparql.Error.TYPE ("`%s' is not a valid boolean".printf (binding.literal)); - } - } else if (binding.data_type == PropertyType.DATE) { - stmt.bind_int (i, (int) string_to_date (binding.literal + "T00:00:00Z", null)); - } else if (binding.data_type == PropertyType.DATETIME) { - stmt.bind_double (i, string_to_date (binding.literal, null)); - } else if (binding.data_type == PropertyType.INTEGER) { - stmt.bind_int (i, int.parse (binding.literal)); - } else { - stmt.bind_text (i, binding.literal); - } - i++; - } - - return stmt; - } - - private DBCursor? exec_sql_cursor (DBInterface iface, string sql, PropertyType[]? types, string[]? variable_names) throws DBInterfaceError, Sparql.Error, DateError { - var stmt = prepare_for_exec (iface, sql); - - return stmt.start_sparql_cursor (types, variable_names); - } - - private string get_select_query (out SelectContext context) throws DBInterfaceError, Sparql.Error, DateError { - // SELECT query - - // build SQL - var sql = new StringBuilder (); - context = pattern.translate_select (sql); - - expect (SparqlTokenType.EOF); - - return sql.str; - } - - private DBCursor? execute_select_cursor () throws DBInterfaceError, Sparql.Error, DateError { - SelectContext context; - string sql = get_select_query (out context); - var iface = manager.get_db_interface (); - - return exec_sql_cursor (iface, sql, context.types, context.variable_names); - } - - private string get_ask_query () throws DBInterfaceError, Sparql.Error, DateError { - // ASK query - - var pattern_sql = new StringBuilder (); - - // build SQL - var sql = new StringBuilder (); - sql.append ("SELECT CASE EXISTS ( "); - - expect (SparqlTokenType.ASK); - - optional (SparqlTokenType.WHERE); - - context = pattern.translate_group_graph_pattern (pattern_sql); - - // select from results of WHERE clause - sql.append (pattern_sql.str); - sql.append (" ) WHEN 1 THEN 'true' WHEN 0 THEN 'false' ELSE NULL END"); - - if (accept (SparqlTokenType.GROUP) || accept (SparqlTokenType.ORDER) || - accept (SparqlTokenType.OFFSET) || accept (SparqlTokenType.LIMIT)) { - throw get_error ("invalid use of %s in ASK".printf (last().to_string())); - } - - expect (SparqlTokenType.EOF); - - context = context.parent_context; - - return sql.str; - } - - private DBCursor? execute_ask_cursor () throws DBInterfaceError, Sparql.Error, DateError { - var iface = manager.get_db_interface (); - return exec_sql_cursor (iface, get_ask_query (), new PropertyType[] { PropertyType.BOOLEAN }, new string[] { "result" }); - } - - private void parse_from_or_into_param () throws Sparql.Error { - if (accept (SparqlTokenType.IRI_REF)) { - current_graph = get_last_string (1); - } else if (accept (SparqlTokenType.PN_PREFIX)) { - string ns = get_last_string (); - expect (SparqlTokenType.COLON); - current_graph = resolve_prefixed_name (ns, get_last_string ().substring (1)); - } else { - expect (SparqlTokenType.COLON); - current_graph = resolve_prefixed_name ("", get_last_string ().substring (1)); - } - } - - private void execute_insert_delete (VariantBuilder? update_blank_nodes) throws GLib.Error { - bool blank = true; - - // DELETE and/or INSERT - - if (accept (SparqlTokenType.WITH)) { - parse_from_or_into_param (); - } else { - current_graph = null; - } - - SourceLocation? delete_location = null; - SourceLocation? insert_location = null; - bool insert_is_update = false; - bool delete_where = false; - bool data = false; - - var data_update = manager.get_data (); - - // Sparql 1.1 defines deletes/inserts as a single - // operation with the syntax: - // [DELETE {...}] [INSERT {...}] WHERE {...} - - if (accept (SparqlTokenType.DELETE)) { - blank = false; - - // SILENT => ignore (non-syntax) errors - silent = accept (SparqlTokenType.SILENT); - - if (current_graph == null && accept (SparqlTokenType.FROM)) { - parse_from_or_into_param (); - } - - if (current_graph == null && accept (SparqlTokenType.DATA)) { - // INSERT/DELETE DATA are simpler variants - // that don't support variables - data = true; - } else if (accept (SparqlTokenType.WHERE)) { - // DELETE WHERE is a short form where the pattern - // is also used as the template for deletion - delete_where = true; - } - - delete_location = get_location (); - - if (!data && !delete_where) { - skip_braces (); - } - } - - if (!data && !delete_where && accept (SparqlTokenType.INSERT)) { - if (accept (SparqlTokenType.OR)) { - expect (SparqlTokenType.REPLACE); - insert_is_update = true; - } - - if (!insert_is_update) { - // SILENT => ignore (non-syntax) errors - silent = accept (SparqlTokenType.SILENT); - } - - if (current_graph == null && accept (SparqlTokenType.INTO)) { - parse_from_or_into_param (); - } - - if (current_graph == null && accept (SparqlTokenType.DATA)) { - // INSERT/DELETE DATA are simpler variants - // that don't support variables - data = true; - } - - if (current () != SparqlTokenType.OPEN_BRACE) { - throw get_error ("Expected '{' beginning a quad data/pattern block"); - } - - insert_location = get_location (); - - if (!data) { - skip_braces (); - } - } - - var pattern_sql = new StringBuilder (); - - var sql = new StringBuilder (); - - if (!data) { - if (delete_where || accept (SparqlTokenType.WHERE)) { - pattern.current_graph = current_graph; - context = pattern.translate_group_graph_pattern (pattern_sql); - pattern.current_graph = null; - } else { - context = new Context (this); - - pattern_sql.append ("SELECT 1"); - } - } else { - // WHERE pattern not supported for INSERT/DELETE DATA, - // nor unbound values in the quad data. - if (quad_data_unbound_var_count () > 0) { - throw get_error ("INSERT/DELETE DATA do not allow unbound values"); - } - - context = new Context (this); - - pattern_sql.append ("SELECT 1"); - } - - var after_where = get_location (); - - var solution = new Solution (); - - // build SQL - sql.append ("SELECT "); - int var_idx = 0; - foreach (var variable in context.var_set.get_keys ()) { - if (var_idx > 0) { - sql.append (", "); - } - - if (variable.binding == null) { - throw get_error ("use of undefined variable `%s'".printf (variable.name)); - } - Expression.append_expression_as_string (sql, variable.sql_expression, variable.binding.data_type); - - solution.hash.insert (variable.name, var_idx++); - } - - if (var_idx == 0) { - sql.append ("1"); - } - - // select from results of WHERE clause - sql.append (" FROM ("); - sql.append (pattern_sql.str); - sql.append (")"); - - var iface = manager.get_writable_db_interface (); - var cursor = exec_sql_cursor (iface, sql.str, null, null); - - int n_solutions = 0; - while (cursor.next ()) { - // get values of all variables to be bound - for (var_idx = 0; var_idx < solution.hash.size (); var_idx++) { - solution.values.add (cursor.get_string (var_idx)); - } - n_solutions++; - } - - cursor = null; - - // Iterate over all solutions twice - // First handle deletes - if (delete_location != null) { - for (int i = 0; i < n_solutions; i++) { - solution.solution_index = i; - set_location (delete_location); - parse_construct_triples_block (solution, UpdateType.DELETE); - data_update.update_buffer_might_flush (); - } - - // Force flush on delete/insert operations, - // so the elements are already removed at - // the time of insertion. - if (insert_location != null) - data_update.update_buffer_flush (); - } - - // Then handle inserts/updates - if (insert_location != null) { - for (int i = 0; i < n_solutions; i++) { - uuid_generate (base_uuid); - blank_nodes = new HashTable<string,string>.full (str_hash, str_equal, g_free, g_free); - solution.solution_index = i; - - set_location (insert_location); - parse_construct_triples_block (solution, - insert_is_update ? - UpdateType.UPDATE : - UpdateType.INSERT); - - if (blank && update_blank_nodes != null) { - update_blank_nodes.add_value (blank_nodes); - } - - data_update.update_buffer_might_flush (); - } - } - - solution = null; - - if (!data) { - // reset location to the end of the update - set_location (after_where); - } - - // ensure possible WHERE clause in next part gets the correct results - data_update.update_buffer_flush (); - bindings = null; - - context = context.parent_context; - } - - internal string resolve_prefixed_name (string prefix, string local_name) throws Sparql.Error { - string ns = prefix_map.lookup (prefix); - if (ns == null) { - throw get_error ("use of undefined prefix `%s'".printf (prefix)); - } - return ns + local_name; - } - - private int quad_data_unbound_var_count () throws Sparql.Error { - SourceLocation current_pos = get_location (); - int n_braces = 1; - int n_unbound = 0; - - expect (SparqlTokenType.OPEN_BRACE); - while (n_braces > 0) { - if (accept (SparqlTokenType.OPEN_BRACE)) { - n_braces++; - } else if (accept (SparqlTokenType.CLOSE_BRACE)) { - n_braces--; - } else if (current () == SparqlTokenType.EOF) { - throw get_error ("unexpected end of query, expected }"); - } else { - if (current () == SparqlTokenType.VAR) - n_unbound++; - // ignore everything else - next (); - } - } - - set_location (current_pos); - return n_unbound; - } - - private void skip_braces () throws Sparql.Error { - expect (SparqlTokenType.OPEN_BRACE); - int n_braces = 1; - while (n_braces > 0) { - if (accept (SparqlTokenType.OPEN_BRACE)) { - n_braces++; - } else if (accept (SparqlTokenType.CLOSE_BRACE)) { - n_braces--; - } else if (current () == SparqlTokenType.EOF) { - throw get_error ("unexpected end of query, expected }"); - } else { - // ignore everything else - next (); - } - } - } - - private void parse_construct_triples_block (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError { - expect (SparqlTokenType.OPEN_BRACE); - - while (current () != SparqlTokenType.CLOSE_BRACE) { - bool is_null = false; - - if (accept (SparqlTokenType.GRAPH)) { - var old_graph = current_graph; - current_graph = parse_construct_var_or_term (var_value_map, type, out is_null); - - if (is_null) { - throw get_error ("'null' not supported for graph"); - } - - expect (SparqlTokenType.OPEN_BRACE); - - while (current () != SparqlTokenType.CLOSE_BRACE) { - current_subject = parse_construct_var_or_term (var_value_map, type, out is_null); - - if (is_null) { - throw get_error ("'null' not supported for subject"); - } - - parse_construct_property_list_not_empty (var_value_map, type); - if (!accept (SparqlTokenType.DOT)) { - // no triples following - break; - } - } - - expect (SparqlTokenType.CLOSE_BRACE); - - current_graph = old_graph; - - optional (SparqlTokenType.DOT); - } else { - current_subject = parse_construct_var_or_term (var_value_map, type, out is_null); - - if (is_null) { - throw get_error ("'null' not supported for subject"); - } - - parse_construct_property_list_not_empty (var_value_map, type); - if (!accept (SparqlTokenType.DOT) && current () != SparqlTokenType.GRAPH) { - // neither GRAPH nor triples following - break; - } - } - } - - expect (SparqlTokenType.CLOSE_BRACE); - } - - bool anon_blank_node_open = false; - - private string? parse_construct_var_or_term (Solution var_value_map, UpdateType type, out bool is_null) throws Sparql.Error, DateError { - string result = ""; - is_null = false; - if (current () == SparqlTokenType.VAR) { - next (); - result = var_value_map.lookup (get_last_string ().substring (1)); - } else if (current () == SparqlTokenType.IRI_REF) { - next (); - result = get_last_string (1); - } else if (current () == SparqlTokenType.PN_PREFIX) { - // prefixed name with namespace foo:bar - next (); - string ns = get_last_string (); - expect (SparqlTokenType.COLON); - result = resolve_prefixed_name (ns, get_last_string ().substring (1)); - } else if (current () == SparqlTokenType.COLON) { - // prefixed name without namespace :bar - next (); - result = resolve_prefixed_name ("", get_last_string ().substring (1)); - } else if (accept (SparqlTokenType.BLANK_NODE)) { - // _:foo - expect (SparqlTokenType.COLON); - result = generate_bnodeid (get_last_string ().substring (1)); - } else if (current () == SparqlTokenType.MINUS) { - next (); - if (current () == SparqlTokenType.INTEGER || - current () == SparqlTokenType.DECIMAL || - current () == SparqlTokenType.DOUBLE) { - next (); - result = "-" + get_last_string (); - } else { - throw get_error ("expected variable or term"); - } - } else if (current () == SparqlTokenType.INTEGER) { - next (); - result = get_last_string (); - } else if (current () == SparqlTokenType.NULL) { - next (); - result = "null"; - is_null = true; - } else if (current () == SparqlTokenType.DECIMAL) { - next (); - result = get_last_string (); - } else if (current () == SparqlTokenType.DOUBLE) { - next (); - result = get_last_string (); - } else if (current () == SparqlTokenType.TRUE) { - next (); - result = "true"; - } else if (current () == SparqlTokenType.FALSE) { - next (); - result = "false"; - } else if (current () == SparqlTokenType.STRING_LITERAL1) { - result = expression.parse_string_literal (); - } else if (current () == SparqlTokenType.STRING_LITERAL2) { - result = expression.parse_string_literal (); - } else if (current () == SparqlTokenType.STRING_LITERAL_LONG1) { - result = expression.parse_string_literal (); - } else if (current () == SparqlTokenType.STRING_LITERAL_LONG2) { - result = expression.parse_string_literal (); - } else if (current () == SparqlTokenType.OPEN_BRACKET) { - - if (anon_blank_node_open) { - throw get_error ("no support for nested anonymous blank nodes"); - } - - anon_blank_node_open = true; - next (); - - result = generate_bnodeid (null); - - string old_subject = current_subject; - bool old_subject_is_var = current_subject_is_var; - - current_subject = result; - parse_construct_property_list_not_empty (var_value_map, type); - expect (SparqlTokenType.CLOSE_BRACKET); - anon_blank_node_open = false; - - current_subject = old_subject; - current_subject_is_var = old_subject_is_var; - } else { - throw get_error ("expected variable or term"); - } - return result; - } - - private void parse_construct_property_list_not_empty (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError { - while (true) { - var old_predicate = current_predicate; - - current_predicate = null; - if (current () == SparqlTokenType.VAR) { - current_predicate_is_var = true; - next (); - current_predicate = var_value_map.lookup (get_last_string ().substring (1)); - } else if (current () == SparqlTokenType.IRI_REF) { - next (); - current_predicate = get_last_string (1); - } else if (current () == SparqlTokenType.PN_PREFIX) { - next (); - string ns = get_last_string (); - expect (SparqlTokenType.COLON); - current_predicate = resolve_prefixed_name (ns, get_last_string ().substring (1)); - } else if (current () == SparqlTokenType.COLON) { - next (); - current_predicate = resolve_prefixed_name ("", get_last_string ().substring (1)); - } else if (current () == SparqlTokenType.A) { - next (); - current_predicate = "http://www.w3.org/1999/02/22-rdf-syntax-ns#type"; - } else { - throw get_error ("expected non-empty property list"); - } - parse_construct_object_list (var_value_map, type); - - current_predicate = old_predicate; - - if (accept (SparqlTokenType.SEMICOLON)) { - continue; - } - break; - } - } - - private void parse_construct_object_list (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError { - while (true) { - parse_construct_object (var_value_map, type); - if (accept (SparqlTokenType.COMMA)) { - continue; - } - break; - } - } - - private void parse_construct_object (Solution var_value_map, UpdateType type) throws Sparql.Error, DateError { - bool is_null = false; - string object = parse_construct_var_or_term (var_value_map, type, out is_null); - var data = manager.get_data (); - if (current_subject == null || current_predicate == null || object == null) { - // the SPARQL specification says that triples containing unbound variables - // should be excluded from the output RDF graph of CONSTRUCT - return; - } - try { - if (type == UpdateType.UPDATE) { - // update triple in database - data.update_statement (current_graph, current_subject, current_predicate, is_null ? null : object); - } else if (type == UpdateType.DELETE) { - // delete triple from database - if (is_null) { - throw get_error ("'null' not supported in this mode"); - } - data.delete_statement (current_graph, current_subject, current_predicate, object); - } else if (type == UpdateType.INSERT) { - // insert triple into database - if (is_null) { - throw get_error ("'null' not supported in this mode"); - } - data.insert_statement (current_graph, current_subject, current_predicate, object); - } - } catch (Sparql.Error e) { - if (!silent) { - throw e; - } - } catch (DateError e) { - if (!silent) { - throw new Sparql.Error.TYPE (e.message); - } - } - } - - [CCode (cname = "uuid_generate")] - public extern static void uuid_generate ([CCode (array_length = false)] uchar[] uuid); -} - |