[tracker/wip/carlosg/sparql-parser-ng: 12/56] libtracker-data: Add TrackerSparqlParser and helpers
- From: Carlos Garnacho <carlosg src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [tracker/wip/carlosg/sparql-parser-ng: 12/56] libtracker-data: Add TrackerSparqlParser and helpers
- Date: Tue, 13 Nov 2018 10:20:52 +0000 (UTC)
commit 6dfed830f1811692ec2e027e2b6ad3d75c6fb480
Author: Carlos Garnacho <carlosg gnome org>
Date: Thu Nov 9 18:03:48 2017 +0100
libtracker-data: Add TrackerSparqlParser and helpers
This struct takes the query text and a root rule that will work as the
starting point to generate the expression tree that represents the query.
This expression tree has a virtually identical structure to the formed
by the rules themselves, with the only difference that ?/+/* rules may
have none or many nodes representing a single rule.
The parser does not do anything beyond a syntactic interpretation of the
query, the expression tree nodes contain a pointer to the rule that
generated them, plus start/end points of the text in the query, so an
upper layer can do the actual ontology validations, and generate the SQL.
The two entry points are tracker_sparql_parse_query/update, that correspond
to the QueryUnit/UpdateUnit entry points defined in the SPARQL grammar.
src/libtracker-data/meson.build | 1 +
src/libtracker-data/tracker-sparql-parser.c | 874 ++++++++++++++++++++++++++++
src/libtracker-data/tracker-sparql-parser.h | 52 ++
3 files changed, 927 insertions(+)
---
diff --git a/src/libtracker-data/meson.build b/src/libtracker-data/meson.build
index ae4487496..aecd15a65 100644
--- a/src/libtracker-data/meson.build
+++ b/src/libtracker-data/meson.build
@@ -58,6 +58,7 @@ libtracker_data = library('tracker-data',
'tracker-ontology.c',
'tracker-ontologies.c',
'tracker-property.c',
+ 'tracker-sparql-parser.c',
tracker_common_enum_header,
tracker_data_enums[0],
tracker_data_enums[1],
diff --git a/src/libtracker-data/tracker-sparql-parser.c b/src/libtracker-data/tracker-sparql-parser.c
new file mode 100644
index 000000000..d6cc6e532
--- /dev/null
+++ b/src/libtracker-data/tracker-sparql-parser.c
@@ -0,0 +1,874 @@
+/*
+ * Copyright (C) 2008-2010, Nokia
+ * Copyright (C) 2018, Red Hat Inc.
+ *
+ * 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.
+ */
+#include "config.h"
+
+#include "tracker-sparql-query.h"
+#include "tracker-sparql-parser.h"
+#include "tracker-sparql-grammar.h"
+
+#include "string.h"
+
+typedef struct _TrackerRuleState TrackerRuleState;
+typedef struct _TrackerNodeTree TrackerNodeTree;
+typedef struct _TrackerParserNode TrackerParserNode;
+typedef struct _TrackerParserState TrackerParserState;
+typedef struct _TrackerGrammarParser TrackerGrammarParser;
+
+#define NODES_PER_CHUNK 128
+#define RULE_STATE_DEFAULT_SIZE 128
+
+struct _TrackerRuleState {
+ const TrackerGrammarRule *rule;
+ TrackerParserNode *node;
+ gssize start_pos;
+ gint cur_child;
+ guint visited : 1;
+ guint finished : 1;
+};
+
+struct _TrackerNodeTree {
+ GPtrArray *chunks;
+ gint current;
+ TrackerParserNode *root;
+};
+
+struct _TrackerParserNode {
+ GNode node;
+ const TrackerGrammarRule *rule;
+ gssize start;
+ gssize end;
+ guint n_children;
+ gint cur_child;
+};
+
+struct _TrackerParserState {
+ TrackerParserNode *root;
+ TrackerNodeTree *node_tree;
+ gssize current;
+ struct {
+ TrackerRuleState *rules;
+ guint array_size;
+ guint len;
+ } rule_states;
+
+
+ const TrackerGrammarRule *error_rule;
+ gssize error_len;
+};
+
+struct _TrackerGrammarParser {
+ const gchar *query;
+ gsize query_len;
+};
+
+static void tracker_grammar_rule_print_helper (GString *str,
+ const TrackerGrammarRule *rule,
+ gint depth);
+
+static void
+tracker_grammar_rule_print_children (GString *str,
+ const TrackerGrammarRule *rules,
+ const gchar *start,
+ const gchar *sep,
+ const gchar *end,
+ gint depth)
+{
+ gint i;
+
+ g_string_append (str, start);
+
+ for (i = 0; rules[i].type != RULE_TYPE_NIL; i++) {
+ if (i != 0)
+ g_string_append (str, sep);
+ tracker_grammar_rule_print_helper (str, &rules[i], depth);
+ }
+
+ g_string_append (str, end);
+}
+
+static void
+tracker_grammar_rule_print_helper (GString *str,
+ const TrackerGrammarRule *rule,
+ gint depth)
+{
+ if (depth == 0) {
+ g_string_append (str, "…");
+ return;
+ }
+
+ depth--;
+
+ switch (rule->type) {
+ case RULE_TYPE_LITERAL:
+ g_string_append_printf (str, "'%s'", rule->string);
+ break;
+ case RULE_TYPE_RULE:
+ case RULE_TYPE_TERMINAL:
+ g_string_append_printf (str, "%s", rule->string);
+ break;
+ case RULE_TYPE_SEQUENCE:
+ tracker_grammar_rule_print_children (str, rule->data.children,
+ "(", " ", ")", depth);
+ break;
+ case RULE_TYPE_OR:
+ tracker_grammar_rule_print_children (str, rule->data.children,
+ "(", " | ", ")", depth);
+ break;
+ case RULE_TYPE_GTE0:
+ tracker_grammar_rule_print_children (str, rule->data.children,
+ "(", " ", ")*", depth);
+ break;
+ case RULE_TYPE_GT0:
+ tracker_grammar_rule_print_children (str, rule->data.children,
+ "(", " ", ")+", depth);
+ break;
+ case RULE_TYPE_OPTIONAL:
+ tracker_grammar_rule_print_children (str, rule->data.children,
+ "(", " ", ")?", depth);
+ break;
+ case RULE_TYPE_NIL:
+ break;
+ }
+}
+
+static gchar *
+tracker_grammar_rule_print (const TrackerGrammarRule *rule)
+{
+ GString *str;
+
+ str = g_string_new (NULL);
+ tracker_grammar_rule_print_helper (str, rule, 5);
+ return g_string_free (str, FALSE);
+}
+
+static TrackerNodeTree *
+tracker_node_tree_new (void)
+{
+ TrackerNodeTree *tree;
+
+ tree = g_slice_new0 (TrackerNodeTree);
+ tree->chunks = g_ptr_array_new_with_free_func (g_free);
+
+ return tree;
+}
+
+void
+tracker_node_tree_free (TrackerNodeTree *tree)
+{
+ g_ptr_array_unref (tree->chunks);
+ g_slice_free (TrackerNodeTree, tree);
+}
+
+TrackerParserNode *
+tracker_node_tree_get_root (TrackerNodeTree *tree)
+{
+ return tree->root;
+}
+
+static inline TrackerParserNode *
+tracker_node_tree_allocate (TrackerNodeTree *tree)
+{
+ TrackerParserNode *node_array;
+ guint chunk, chunk_idx;
+
+ chunk = tree->current / NODES_PER_CHUNK;
+ chunk_idx = tree->current % NODES_PER_CHUNK;
+ tree->current++;
+
+ if (chunk >= tree->chunks->len) {
+ node_array = g_new0 (TrackerParserNode, NODES_PER_CHUNK);
+ g_ptr_array_add (tree->chunks, node_array);
+ } else {
+ node_array = g_ptr_array_index (tree->chunks, chunk);
+ }
+
+ return &node_array[chunk_idx];
+}
+
+static void
+tracker_node_tree_reset (TrackerNodeTree *tree,
+ TrackerParserNode *node)
+{
+ gint i;
+
+ if (!node)
+ return;
+
+ g_node_unlink ((GNode *) node);
+
+ for (i = tree->chunks->len - 1; i >= 0; i--) {
+ TrackerParserNode *range = g_ptr_array_index (tree->chunks, i);
+
+ if (node >= range && node < &range[NODES_PER_CHUNK]) {
+ guint pos = node - range;
+ tree->current = (i * NODES_PER_CHUNK) + pos;
+ return;
+ }
+ }
+
+ g_assert_not_reached ();
+}
+
+static inline void
+tracker_parser_node_reset (TrackerParserNode *node,
+ const TrackerGrammarRule *rule,
+ const TrackerParserState *state)
+{
+ node->rule = rule;
+ node->start = node->end = state->current;
+
+ switch (rule->type) {
+ case RULE_TYPE_RULE:
+ case RULE_TYPE_SEQUENCE:
+ case RULE_TYPE_GT0:
+ case RULE_TYPE_GTE0:
+ case RULE_TYPE_OPTIONAL:
+ case RULE_TYPE_OR:
+ node->cur_child = -1;
+ break;
+ case RULE_TYPE_LITERAL:
+ case RULE_TYPE_TERMINAL:
+ break;
+ case RULE_TYPE_NIL:
+ g_assert_not_reached ();
+ break;
+ }
+}
+
+static inline TrackerParserNode *
+tracker_parser_node_new (const TrackerGrammarRule *rule,
+ const TrackerParserState *state)
+{
+ TrackerParserNode *node;
+
+ node = tracker_node_tree_allocate (state->node_tree);
+ node->node = (GNode) { node, 0, };
+ tracker_parser_node_reset (node, rule, state);
+
+ return node;
+}
+
+static void
+tracker_grammar_parser_init (TrackerGrammarParser *parser,
+ const gchar *query,
+ gsize len)
+{
+ parser->query = query;
+ parser->query_len = len;
+}
+
+static void
+tracker_parser_state_push (TrackerParserState *state,
+ const TrackerGrammarRule *rule)
+{
+ TrackerRuleState *rule_state;
+
+ state->rule_states.len++;
+
+ if (state->rule_states.len > state->rule_states.array_size) {
+ state->rule_states.array_size <<= 1;
+ state->rule_states.rules = g_realloc_n (state->rule_states.rules,
+ state->rule_states.array_size,
+ sizeof (TrackerRuleState));
+ }
+
+ rule_state = &state->rule_states.rules[state->rule_states.len - 1];
+
+ rule_state->rule = rule;
+ rule_state->node = NULL;
+ rule_state->start_pos = state->current;
+ rule_state->cur_child = 0;
+ rule_state->visited = rule_state->finished = FALSE;
+}
+
+static TrackerRuleState *
+tracker_parser_state_peek (TrackerParserState *state)
+{
+ return &state->rule_states.rules[state->rule_states.len - 1];
+}
+
+static TrackerParserNode *
+tracker_parser_state_pop (TrackerParserState *state)
+{
+ TrackerRuleState *rule_state;
+ TrackerParserNode *node = NULL;
+
+ rule_state = tracker_parser_state_peek (state);
+ if (rule_state->node) {
+ node = rule_state->node;
+ node->end = state->current;
+ }
+
+ state->rule_states.len--;
+
+ return node;
+}
+
+static const TrackerGrammarRule *
+tracker_parser_state_peek_current_rule (TrackerParserState *state)
+{
+ TrackerRuleState *rule_state;
+
+ rule_state = tracker_parser_state_peek (state);
+
+ return rule_state->rule;
+}
+
+static const TrackerGrammarRule *
+tracker_parser_state_lookup_child (TrackerParserState *state)
+{
+ TrackerRuleState *rule_state;
+ const TrackerGrammarRule *children;
+
+ rule_state = tracker_parser_state_peek (state);
+
+ if (rule_state->finished)
+ return NULL;
+
+ if (rule_state->rule->type == RULE_TYPE_LITERAL ||
+ rule_state->rule->type == RULE_TYPE_TERMINAL)
+ return NULL;
+
+ children = tracker_grammar_rule_get_children (rule_state->rule);
+ if (!children)
+ return NULL;
+
+ return &children[rule_state->cur_child];
+}
+
+static inline gboolean
+tracker_parser_state_next_child (TrackerParserState *state,
+ gboolean success)
+{
+ const TrackerGrammarRule *children;
+ TrackerRuleState *rule_state;
+
+ rule_state = tracker_parser_state_peek (state);
+
+ if (rule_state->finished)
+ return FALSE;
+
+ if (success) {
+ if (rule_state->rule->type == RULE_TYPE_OR) {
+ /* Successful OR rules are satisfied already */
+ rule_state->finished = TRUE;
+ return FALSE;
+ } else if (rule_state->rule->type == RULE_TYPE_GT0 ||
+ rule_state->rule->type == RULE_TYPE_GTE0) {
+ /* Successful + and * rules are evaluated again */
+ return TRUE;
+ }
+ } else {
+ if (rule_state->rule->type == RULE_TYPE_GT0 ||
+ rule_state->rule->type == RULE_TYPE_GTE0) {
+ rule_state->finished = TRUE;
+ return FALSE;
+ }
+ }
+
+ children = tracker_grammar_rule_get_children (rule_state->rule);
+ if (!children)
+ return FALSE;
+
+ rule_state->cur_child++;
+ rule_state->finished = children[rule_state->cur_child].type == RULE_TYPE_NIL;
+
+ return !rule_state->finished;
+}
+
+static TrackerParserNode *
+tracker_parser_state_transact_match (TrackerParserState *state)
+{
+ TrackerParserNode *parser_node = NULL;
+ guint i;
+
+ for (i = 0; i < state->rule_states.len; i++) {
+ TrackerRuleState *rule_state = &state->rule_states.rules[i];
+
+ rule_state->visited = TRUE;
+
+ if (rule_state->rule->type != RULE_TYPE_LITERAL &&
+ rule_state->rule->type != RULE_TYPE_TERMINAL &&
+ rule_state->rule->type != RULE_TYPE_RULE)
+ continue;
+
+ if (rule_state->node == NULL) {
+ rule_state->node = tracker_parser_node_new (rule_state->rule, state);
+ if (parser_node) {
+ g_node_append ((GNode *) parser_node,
+ (GNode *) rule_state->node);
+ }
+ }
+
+ parser_node = rule_state->node;
+ }
+
+ return parser_node;
+}
+
+static void
+tracker_parser_state_take_error (TrackerParserState *state,
+ const TrackerGrammarRule *rule)
+{
+ if (state->current < state->error_len) {
+ return;
+ }
+
+ state->error_len = state->current;
+ state->error_rule = rule;
+}
+
+static void
+tracker_parser_state_forward (TrackerParserState *state,
+ TrackerGrammarParser *parser,
+ gssize len)
+{
+ g_assert (len >= 0 && state->current + len <= parser->query_len);
+ state->current += len;
+}
+
+static void
+tracker_parser_state_rewind (TrackerParserState *state)
+{
+ TrackerRuleState *rule_state;
+
+ rule_state = tracker_parser_state_peek (state);
+ g_assert (rule_state->start_pos >= 0 && rule_state->start_pos <= state->current);
+ state->current = rule_state->start_pos;
+}
+
+static void
+tracker_parser_state_skip_whitespace (TrackerParserState *state,
+ TrackerGrammarParser *parser)
+{
+ while (state->current < parser->query_len) {
+ /* Skip comments too */
+ if (parser->query[state->current] == '#') {
+ while (state->current < parser->query_len &&
+ parser->query[state->current] != '\n') {
+ tracker_parser_state_forward (state, parser, 1);
+ }
+ }
+
+ if (parser->query[state->current] != ' ' &&
+ parser->query[state->current] != '\n' &&
+ parser->query[state->current] != '\t')
+ break;
+
+ tracker_parser_state_forward (state, parser, 1);
+ }
+}
+
+static gboolean
+tracker_grammar_parser_apply_rule_literal (TrackerGrammarParser *parser,
+ TrackerParserState *state,
+ const TrackerGrammarRule *rule)
+{
+ TrackerParserNode *node;
+ gboolean next_isalnum;
+ gsize len;
+
+ if (rule->string[0] != parser->query[state->current] &&
+ rule->string[0] != g_ascii_tolower (parser->query[state->current]))
+ goto error;
+
+ len = strlen (rule->string);
+ g_assert (len > 0);
+
+ if (state->current + len > parser->query_len)
+ goto error;
+
+ if (len > 1 &&
+ rule->string[len - 1] != parser->query[state->current + len - 1] &&
+ rule->string[len - 1] != g_ascii_tolower (parser->query[state->current + len - 1]))
+ goto error;
+
+ next_isalnum = g_ascii_isalnum (parser->query[state->current + len]);
+
+ /* Special case for '?', which may be a property path operator, and
+ * the beginning of VAR1. If the next char is alphanumeric, it's probably
+ * the latter.
+ */
+ if (rule->data.literal == LITERAL_PATH_OPTIONAL && next_isalnum)
+ goto error;
+
+ /* Generic check for other literals, if the literal is alphanumeric, and
+ * the remaining text starts with alphanumeric, probably that was not it.
+ */
+ if (rule->string[0] >= 'a' && rule->string[0] <= 'z' && next_isalnum)
+ goto error;
+
+ if (len > 1 &&
+ g_ascii_strncasecmp (rule->string, &parser->query[state->current], len) != 0)
+ goto error;
+
+ node = tracker_parser_state_transact_match (state);
+ tracker_parser_state_forward (state, parser, len);
+ node->end = state->current;
+ return TRUE;
+
+error:
+ tracker_parser_state_take_error (state, rule);
+ return FALSE;
+}
+
+static gboolean
+tracker_grammar_parser_apply_rule_terminal (TrackerGrammarParser *parser,
+ TrackerParserState *state,
+ const TrackerGrammarRule *rule)
+{
+ TrackerParserNode *node;
+ TrackerTerminalFunc func;
+ const gchar *str, *end;
+
+ str = &parser->query[state->current];
+
+ if (state->current == parser->query_len || str[0] == '\0') {
+ tracker_parser_state_take_error (state, rule);
+ return FALSE;
+ }
+
+ func = tracker_grammar_rule_get_terminal_func (rule);
+
+ if (!func (str, &parser->query[parser->query_len], &end)) {
+ tracker_parser_state_take_error (state, rule);
+ return FALSE;
+ }
+
+ node = tracker_parser_state_transact_match (state);
+ tracker_parser_state_forward (state, parser, end - str);
+ node->end = state->current;
+ return TRUE;
+}
+
+static gboolean
+tracker_grammar_parser_apply_rule (TrackerGrammarParser *parser,
+ TrackerParserState *state,
+ const TrackerGrammarRule *rule)
+{
+ switch (rule->type) {
+ case RULE_TYPE_LITERAL:
+ return tracker_grammar_parser_apply_rule_literal (parser,
+ state, rule);
+ case RULE_TYPE_TERMINAL:
+ return tracker_grammar_parser_apply_rule_terminal (parser,
+ state, rule);
+ case RULE_TYPE_RULE:
+ case RULE_TYPE_SEQUENCE:
+ case RULE_TYPE_GT0:
+ case RULE_TYPE_GTE0:
+ case RULE_TYPE_OPTIONAL:
+ case RULE_TYPE_OR:
+ return TRUE;
+ case RULE_TYPE_NIL:
+ g_assert_not_reached ();
+ return FALSE;
+ }
+
+ g_assert_not_reached ();
+}
+
+static gboolean
+tracker_parser_state_iterate (TrackerParserState *state,
+ TrackerGrammarParser *parser,
+ gboolean try_children)
+{
+ const TrackerGrammarRule *child;
+
+ if (try_children) {
+ /* Try iterating into children first */
+ tracker_parser_state_peek_current_rule (state);
+ child = tracker_parser_state_lookup_child (state);
+
+ if (child) {
+ tracker_parser_state_push (state, child);
+ return TRUE;
+ }
+ }
+
+ tracker_parser_state_pop (state);
+
+ /* Find the first parent that has a next child to handle */
+ while (state->rule_states.len > 0) {
+ tracker_parser_state_peek_current_rule (state);
+
+ if (tracker_parser_state_next_child (state, TRUE)) {
+ child = tracker_parser_state_lookup_child (state);
+ tracker_parser_state_push (state, child);
+ return TRUE;
+ }
+
+ tracker_parser_state_pop (state);
+ }
+
+ return FALSE;
+}
+
+static gboolean
+tracker_parser_state_rollback (TrackerParserState *state,
+ TrackerGrammarParser *parser)
+{
+ const TrackerGrammarRule *rule, *child;
+ TrackerParserNode *node, *discard;
+
+ /* Reset state to retry again the failed portions */
+ tracker_parser_state_rewind (state);
+ discard = tracker_parser_state_pop (state);
+
+ while (state->rule_states.len > 0) {
+ rule = tracker_parser_state_peek_current_rule (state);
+
+ switch (rule->type) {
+ case RULE_TYPE_OR:
+ if (tracker_parser_state_next_child (state, FALSE)) {
+ tracker_node_tree_reset (state->node_tree, discard);
+ child = tracker_parser_state_lookup_child (state);
+ tracker_parser_state_push (state, child);
+ return TRUE;
+ }
+ break;
+ case RULE_TYPE_GT0:
+ /* If we errored out the first time we
+ * parse ()+, raise an error.
+ */
+ if (!tracker_parser_state_peek (state)->visited)
+ break;
+
+ /* Fall through */
+ case RULE_TYPE_GTE0:
+ case RULE_TYPE_OPTIONAL:
+ tracker_parser_state_iterate (state, parser, FALSE);
+ tracker_node_tree_reset (state->node_tree, discard);
+ return TRUE;
+ case RULE_TYPE_RULE:
+ tracker_parser_state_take_error (state, rule);
+ break;
+ default:
+ break;
+ }
+
+ /* Reset state to retry again the failed portions */
+ tracker_parser_state_rewind (state);
+ node = tracker_parser_state_pop (state);
+ if (node)
+ discard = node;
+ }
+
+ return FALSE;
+}
+
+static gboolean
+tracker_grammar_parser_read (TrackerGrammarParser *parser,
+ TrackerParserState *state)
+{
+
+ while (state->rule_states.len > 0) {
+ const TrackerGrammarRule *rule;
+
+ tracker_parser_state_skip_whitespace (state, parser);
+ rule = tracker_parser_state_peek_current_rule (state);
+
+ if (tracker_grammar_parser_apply_rule (parser, state, rule)) {
+ if (!tracker_parser_state_iterate (state, parser, TRUE))
+ break;
+ } else {
+ if (!tracker_parser_state_rollback (state, parser))
+ break;
+
+ /* We rolled back successfully, keep going. */
+ tracker_parser_state_take_error (state, NULL);
+ }
+ }
+
+ return state->error_rule == NULL;
+}
+
+static void
+tracker_parser_state_propagate_error (TrackerParserState *state,
+ GError **error)
+{
+ const TrackerGrammarRule *rule = state->error_rule;
+ gchar *expected;
+
+ if (rule->type == RULE_TYPE_LITERAL)
+ expected = g_strdup_printf ("literal '%s'", rule->string);
+ else if (rule->type == RULE_TYPE_TERMINAL)
+ expected = g_strdup_printf ("terminal '%s'", rule->string);
+ else
+ expected = tracker_grammar_rule_print (rule);
+
+ g_set_error (error,
+ TRACKER_SPARQL_ERROR,
+ TRACKER_SPARQL_ERROR_PARSE,
+ "Parser error at byte %ld: Expected %s",
+ state->error_len, expected);
+
+ g_free (expected);
+}
+
+TrackerNodeTree *
+tracker_grammar_parser_apply (TrackerGrammarParser *parser,
+ const TrackerGrammarRule *rule,
+ gsize *len_out,
+ GError **error)
+{
+ TrackerParserState state = { 0, };
+
+ state.node_tree = tracker_node_tree_new ();
+ state.rule_states.array_size = RULE_STATE_DEFAULT_SIZE;
+ state.rule_states.rules = g_new0 (TrackerRuleState,
+ state.rule_states.array_size);
+
+ tracker_parser_state_push (&state, rule);
+ state.node_tree->root = tracker_parser_state_transact_match (&state);
+
+ if (!tracker_grammar_parser_read (parser, &state)) {
+ tracker_parser_state_propagate_error (&state, error);
+ g_free (state.rule_states.rules);
+ return NULL;
+ }
+
+ if (len_out)
+ *len_out = state.current;
+
+ g_free (state.rule_states.rules);
+
+ return state.node_tree;
+}
+
+TrackerNodeTree *
+tracker_sparql_parse_query (const gchar *query,
+ gssize len,
+ gsize *len_out,
+ GError **error)
+{
+ TrackerGrammarParser parser;
+ TrackerNodeTree *tree;
+
+ g_return_val_if_fail (query != NULL, NULL);
+
+ if (len < 0)
+ len = strlen (query);
+
+ tracker_grammar_parser_init (&parser, query, len);
+ tree = tracker_grammar_parser_apply (&parser, NAMED_RULE (QueryUnit), len_out, error);
+
+ return tree;
+}
+
+TrackerNodeTree *
+tracker_sparql_parse_update (const gchar *query,
+ gssize len,
+ gsize *len_out,
+ GError **error)
+{
+ TrackerGrammarParser parser;
+ TrackerNodeTree *tree;
+
+ g_return_val_if_fail (query != NULL, NULL);
+
+ if (len < 0)
+ len = strlen (query);
+
+ tracker_grammar_parser_init (&parser, query, len);
+ tree = tracker_grammar_parser_apply (&parser, NAMED_RULE (UpdateUnit), len_out, error);
+
+ return tree;
+}
+
+const TrackerGrammarRule *
+tracker_parser_node_get_rule (TrackerParserNode *node)
+{
+ return node->rule;
+}
+
+gboolean
+tracker_parser_node_get_extents (TrackerParserNode *node,
+ gssize *start,
+ gssize *end)
+{
+ if (start)
+ *start = node->start;
+ if (end)
+ *end = node->end;
+
+ return node->end != node->start;
+}
+
+TrackerParserNode *
+tracker_sparql_parser_tree_find_first (TrackerParserNode *node,
+ gboolean leaves_only)
+{
+ g_return_val_if_fail (node != NULL, NULL);
+
+ while (node) {
+ if ((!leaves_only && node->rule->type == RULE_TYPE_RULE) ||
+ node->rule->type == RULE_TYPE_LITERAL ||
+ node->rule->type == RULE_TYPE_TERMINAL) {
+ return node;
+ } else if (!node->node.children) {
+ return tracker_sparql_parser_tree_find_next (node, leaves_only);
+ }
+
+ node = (TrackerParserNode *) node->node.children;
+ }
+
+ return NULL;
+}
+
+TrackerParserNode *
+tracker_sparql_parser_tree_find_next (TrackerParserNode *node,
+ gboolean leaves_only)
+{
+ g_return_val_if_fail (node != NULL, NULL);
+
+ while (TRUE) {
+ if (node->node.children)
+ node = (TrackerParserNode *) node->node.children;
+ else if (node->node.next)
+ node = (TrackerParserNode *) node->node.next;
+ else if (node->node.parent) {
+ node = (TrackerParserNode *) node->node.parent;
+
+ /* Traverse up all parents till we find one
+ * with a next node.
+ */
+ while (node) {
+ if (node->node.next) {
+ node = (TrackerParserNode *) node->node.next;
+ break;
+ }
+
+ node = (TrackerParserNode *) node->node.parent;
+ }
+ }
+
+ if (!node)
+ break;
+
+ if ((!leaves_only && node->rule->type == RULE_TYPE_RULE) ||
+ node->rule->type == RULE_TYPE_LITERAL ||
+ node->rule->type == RULE_TYPE_TERMINAL) {
+ return node;
+ }
+ }
+
+ return NULL;
+}
diff --git a/src/libtracker-data/tracker-sparql-parser.h b/src/libtracker-data/tracker-sparql-parser.h
new file mode 100644
index 000000000..a0c755948
--- /dev/null
+++ b/src/libtracker-data/tracker-sparql-parser.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2008-2010, Nokia
+ * Copyright (C) 2018, Red Hat Inc.
+ *
+ * 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.
+ */
+#ifndef __TRACKER_SPARQL_PARSER_H__
+#define __TRACKER_SPARQL_PARSER_H__
+
+#include <glib.h>
+
+typedef struct _TrackerParserNode TrackerParserNode;
+typedef struct _TrackerGrammarRule TrackerGrammarRule;
+typedef struct _TrackerNodeTree TrackerNodeTree;
+
+TrackerNodeTree * tracker_sparql_parse_query (const gchar *query,
+ gssize len,
+ gsize *len_out,
+ GError **error);
+TrackerNodeTree * tracker_sparql_parse_update (const gchar *query,
+ gssize len,
+ gsize *len_out,
+ GError **error);
+
+void tracker_node_tree_free (TrackerNodeTree *tree);
+TrackerParserNode * tracker_node_tree_get_root (TrackerNodeTree *tree);
+
+TrackerParserNode * tracker_sparql_parser_tree_find_first (TrackerParserNode *node,
+ gboolean leaves_only);
+TrackerParserNode * tracker_sparql_parser_tree_find_next (TrackerParserNode *node,
+ gboolean leaves_only);
+
+const TrackerGrammarRule * tracker_parser_node_get_rule (TrackerParserNode *node);
+
+gboolean tracker_parser_node_get_extents (TrackerParserNode *node,
+ gssize *start,
+ gssize *end);
+
+#endif /* __TRACKER_SPARQL_PARSER_H__ */
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