/src/libxmlb/src/xb-silo-query.c

Source
/*
 * Copyright 2018 Richard Hughes <richard@hughsie.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#define G_LOG_DOMAIN "XbSilo"

#include "config.h"

#include <gio/gio.h>
#include <string.h>

#include "xb-node-private.h"
#include "xb-opcode-private.h"
#include "xb-opcode.h"
#include "xb-query-private.h"
#include "xb-silo-node.h"
#include "xb-silo-query-private.h"
#include "xb-stack-private.h"
#include "xb-value-bindings-private.h"

#define XB_QUERY_OR_BRANCH_MAX 64

static gboolean
xb_silo_query_node_matches(XbSilo *self,
         XbMachine *machine,
         XbSiloNode *sn,
         XbQuerySection *section,
         XbSiloQueryData *query_data,
         XbValueBindings *bindings,
         guint bindings_offset,
         guint *bindings_offset_end_out,
         gboolean *result,
         GError **error)
{
  /* we have an index into the string table */
  if (section->element_idx != sn->element_name &&
      section->kind != XB_SILO_QUERY_KIND_WILDCARD) {
    *result = FALSE;
    return TRUE;
  }

  /* for section */
  query_data->position += 1;

  /* check predicates */
  if (section->predicates != NULL) {
    for (guint i = 0; i < section->predicates->len; i++) {
      XbStack *opcodes = g_ptr_array_index(section->predicates, i);
      g_auto(XbValueBindings) predicate_bindings = XB_VALUE_BINDINGS_INIT();
      guint predicate_bindings_idx = 0;
      XbValueBindings *predicate_bindings_ptr = NULL;

      if (bindings != NULL)
        predicate_bindings_ptr = &predicate_bindings;

      /* set up the bindings for this predicate */
      for (guint k = 0; bindings != NULL && k < xb_stack_get_size(opcodes); k++) {
        XbOpcode *op = xb_stack_peek(opcodes, k);
        if (xb_opcode_is_binding(op)) {
          /* ignore errors as they’ll be caught by xb_machine_run() */
          xb_value_bindings_copy_binding(bindings,
                       bindings_offset +
                     predicate_bindings_idx,
                       &predicate_bindings,
                       predicate_bindings_idx);
          predicate_bindings_idx++;
        }
      }

      /* run the predicate; pass NULL for the bindings iff
       * (bindings == NULL), as that means we’ve been called
       * with pre-0.3.0-style pre-bound values */
      if (!xb_machine_run_with_bindings(machine,
                opcodes,
                predicate_bindings_ptr,
                result,
                query_data,
                error))
        return FALSE;

      bindings_offset += predicate_bindings_idx;
    }
  }

  if (bindings_offset_end_out != NULL)
    *bindings_offset_end_out = bindings_offset;

  /* success */
  return TRUE;
}

/**
 * XbSiloQueryHelperFlags:
 * @XB_SILO_QUERY_HELPER_NONE: No flags set.
 * @XB_SILO_QUERY_HELPER_USE_SN: Return #XbSiloNodes as results, rather than
 *    wrapping them in #XbNode. This assumes that they’ll be wrapped later.
 * @XB_SILO_QUERY_HELPER_FORCE_NODE_CACHE: Always cache the #XbNode objects
 *
 * Flags for #XbSiloQueryHelper.
 *
 * Since: 0.2.0
 */
typedef enum {
  XB_SILO_QUERY_HELPER_NONE = 0,
  XB_SILO_QUERY_HELPER_USE_SN = 1 << 0,
  XB_SILO_QUERY_HELPER_FORCE_NODE_CACHE = 1 << 1,
} XbSiloQueryHelperFlags;

typedef struct {
  GPtrArray *sections; /* of XbQuerySection */
  GPtrArray *results;  /* of XbNode or XbSiloNode (see @flags) */
  XbValueBindings *bindings;
  GHashTable *results_hash; /* of sn:1 */
  guint limit;
  XbSiloQueryHelperFlags flags;
  XbSiloQueryData *query_data;
} XbSiloQueryHelper;

static gboolean
xb_silo_query_section_add_result(XbSilo *self, XbSiloQueryHelper *helper, XbSiloNode *sn)
{
  if (g_hash_table_lookup(helper->results_hash, sn) != NULL)
    return FALSE;
  if (helper->flags & XB_SILO_QUERY_HELPER_USE_SN) {
    g_ptr_array_add(helper->results, sn);
  } else {
    gboolean force_node_cache =
        (helper->flags & XB_SILO_QUERY_HELPER_FORCE_NODE_CACHE) > 0;
    g_ptr_array_add(helper->results, xb_silo_create_node(self, sn, force_node_cache));
  }
  g_hash_table_add(helper->results_hash, sn);
  return helper->results->len == helper->limit;
}

/*
 * @parent: (allow-none)
 */
static gboolean
xb_silo_query_section_root(XbSilo *self,
         XbSiloNode *sn,
         guint i,
         guint bindings_offset,
         XbSiloQueryHelper *helper,
         GError **error)
{
  XbMachine *machine = xb_silo_get_machine(self);
  XbSiloQueryData *query_data = helper->query_data;
  XbQuerySection *section = g_ptr_array_index(helper->sections, i);

  /* handle parent */
  if (section->kind == XB_SILO_QUERY_KIND_PARENT) {
    XbSiloNode *parent;
    if (sn == NULL) {
      g_set_error_literal(error,
              G_IO_ERROR,
              G_IO_ERROR_INVALID_ARGUMENT,
              "cannot obtain parent for root");
      return FALSE;
    }
    parent = xb_silo_get_parent_node(self, sn, error);
    if (parent == NULL)
      return FALSE;
    if (i == helper->sections->len - 1) {
      xb_silo_query_section_add_result(self, helper, parent);
      return TRUE;
    }
    return xb_silo_query_section_root(self,
              parent,
              i + 1,
              bindings_offset,
              helper,
              error);
  }

  /* no node means root */
  if (sn == NULL) {
    sn = xb_silo_get_root_node(self, error);
    if (sn == NULL)
      return FALSE;
  } else {
    g_autoptr(GError) error_local = NULL;
    sn = xb_silo_get_child_node(self, sn, &error_local);
    if (sn == NULL) {
      if (g_error_matches(error_local, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT))
        return TRUE;
      g_propagate_error(error, g_steal_pointer(&error_local));
      return FALSE;
    }
  }

  /* set up level pointer */
  query_data->position = 0;

  /* continue matching children ".." */
  do {
    XbSiloNode *sn_new;
    gboolean result = TRUE;
    guint bindings_offset_end = 0;
    query_data->sn = sn;
    if (!xb_silo_query_node_matches(self,
            machine,
            sn,
            section,
            query_data,
            helper->bindings,
            bindings_offset,
            &bindings_offset_end,
            &result,
            error))
      return FALSE;
    if (result) {
      if (i == helper->sections->len - 1) {
        if (xb_silo_query_section_add_result(self, helper, sn))
          break;
      } else {
        if (!xb_silo_query_section_root(self,
                sn,
                i + 1,
                bindings_offset_end,
                helper,
                error))
          return FALSE;
        if (helper->results->len > 0 &&
            helper->results->len == helper->limit)
          break;
      }
    }
    if (sn->next == 0x0)
      break;
    sn_new = xb_silo_get_node(self, sn->next, error);
    if (sn_new == NULL)
      return FALSE;
    if (sn_new <= sn) {
      g_set_error(error,
            G_IO_ERROR,
            G_IO_ERROR_INVALID_DATA,
            "silo node was invalid: %p -> %p",
            sn,
            sn_new);
      return FALSE;
    }
    sn = sn_new;
  } while (TRUE);
  return TRUE;
}

static gboolean
xb_silo_query_part(XbSilo *self,
       XbSiloNode *sroot,
       GPtrArray *results,
       GHashTable *results_hash,
       XbQuery *query,
       XbQueryContext *context,
       gboolean first_result_only,
       XbSiloQueryData *query_data,
       XbSiloQueryHelperFlags flags,
       GError **error)
{
  G_GNUC_BEGIN_IGNORE_DEPRECATIONS
  XbSiloQueryHelper helper = {
      .results = results,
      .bindings = (context != NULL) ? xb_query_context_get_bindings(context) : NULL,
      .limit = first_result_only   ? 1
         : (context != NULL) ? xb_query_context_get_limit(context)
           : xb_query_get_limit(query),
      .flags = flags,
      .results_hash = results_hash,
      .query_data = query_data,
  };
  XbQueryFlags query_flags = (context != NULL) ? xb_query_context_get_flags(context)
                 : xb_query_get_flags(query);
  G_GNUC_END_IGNORE_DEPRECATIONS

  /* find each section */
  helper.sections = xb_query_get_sections(query);
  if (query_flags & XB_QUERY_FLAG_FORCE_NODE_CACHE)
    helper.flags |= XB_SILO_QUERY_HELPER_FORCE_NODE_CACHE;
  return xb_silo_query_section_root(self, sroot, 0, 0, &helper, error);
}

/* Returns an array with (element-type XbSiloNode) if
 * %XB_SILO_QUERY_HELPER_USE_SN is set, and (element-type XbNode) otherwise. */
static GPtrArray *
silo_query_with_root(XbSilo *self,
         XbNode *n,
         const gchar *xpath,
         guint limit,
         XbSiloQueryHelperFlags flags,
         GError **error)
{
  XbSiloNode *sn = NULL;
  g_auto(GStrv) split = NULL;
  g_autoptr(GHashTable) results_hash = g_hash_table_new(g_direct_hash, g_direct_equal);
  g_autoptr(GPtrArray) results = NULL;
  g_autoptr(GTimer) timer = xb_silo_start_profile(self);
  XbSiloQueryData query_data = {
      .sn = NULL,
      .position = 0,
  };

  g_return_val_if_fail(XB_IS_SILO(self), NULL);
  g_return_val_if_fail(xpath != NULL, NULL);
  g_return_val_if_fail(error == NULL || *error == NULL, NULL);

  /* empty silo */
  if (xb_silo_is_empty(self)) {
    g_set_error_literal(error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND, "silo has no data");
    return NULL;
  }

  if (flags & XB_SILO_QUERY_HELPER_USE_SN)
    results = g_ptr_array_new_with_free_func(NULL);
  else
    results = g_ptr_array_new_with_free_func((GDestroyNotify)g_object_unref);

  /* subtree query */
  if (n != NULL) {
    sn = xb_node_get_sn(n);
    if (xpath[0] == '/') {
      g_set_error_literal(error,
              G_IO_ERROR,
              G_IO_ERROR_NOT_SUPPORTED,
              "XPath node query not supported");
      return NULL;
    }
  } else {
    /* assume it's just a root query */
    if (xpath[0] == '/')
      xpath++;
  }

  /* do 'or' searches */
  split = g_strsplit(xpath, "|", XB_QUERY_OR_BRANCH_MAX + 1);
  if (g_strv_length(split) > XB_QUERY_OR_BRANCH_MAX) {
    g_set_error_literal(error,
            G_IO_ERROR,
            G_IO_ERROR_INVALID_DATA,
            "too many OR branches in XPath query");
    return NULL;
  }
  for (guint i = 0; split[i] != NULL; i++) {
    g_autoptr(GError) error_local = NULL;
    g_autoptr(XbQuery) query = xb_query_new(self, split[i], &error_local);
    g_auto(XbQueryContext) context = XB_QUERY_CONTEXT_INIT();

    if (query == NULL) {
      if (g_error_matches(error_local, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT) &&
          (split[i + 1] != NULL || results->len > 0)) {
        if (xb_silo_get_profile_flags(self) & XB_SILO_PROFILE_FLAG_DEBUG) {
          g_debug("ignoring for OR statement: %s",
            error_local->message);
        }
        continue;
      }
      g_propagate_prefixed_error(error,
               g_steal_pointer(&error_local),
               "failed to process %s: ",
               xpath);
      return NULL;
    }

    xb_query_context_set_limit(&context, limit);
    if (!xb_silo_query_part(self,
          sn,
          results,
          results_hash,
          query,
          &context,
          FALSE,
          &query_data,
          flags,
          error)) {
      return NULL;
    }
  }

  /* profile */
  if (xb_silo_get_profile_flags(self) & XB_SILO_PROFILE_FLAG_XPATH) {
    xb_silo_add_profile(self,
            timer,
            "query on %s with `%s` limit=%u -> %u results",
            n != NULL ? xb_node_get_element(n) : "/",
            xpath,
            limit,
            results->len);
  }

  /* nothing found */
  if (results->len == 0) {
    g_set_error(error,
          G_IO_ERROR,
          G_IO_ERROR_NOT_FOUND,
          "no results for XPath query '%s'",
          xpath);
    return NULL;
  }
  return g_steal_pointer(&results);
}

/**
 * xb_silo_query_with_root: (skip)
 * @self: a #XbSilo
 * @n: (allow-none): a #XbNode
 * @xpath: an XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @limit: maximum number of results to return, or 0 for "all"
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query, returning up to @limit results.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a subset of XPath is supported.
 *
 * Returns: (transfer container) (element-type XbNode): results, or %NULL if unfound
 *
 * Since: 0.1.0
 **/
GPtrArray *
xb_silo_query_with_root(XbSilo *self, XbNode *n, const gchar *xpath, guint limit, GError **error)
{
  return silo_query_with_root(self, n, xpath, limit, XB_SILO_QUERY_HELPER_NONE, error);
}

/**
 * xb_silo_query_sn_with_root: (skip)
 * @self: a #XbSilo
 * @n: (allow-none): a #XbNode
 * @xpath: an XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @limit: maximum number of results to return, or 0 for "all"
 * @error: the #GError, or %NULL
 *
 * A version of xb_silo_query_with_root() which returns results as #XbSiloNodes,
 * rather than as #XbNodes. This is intended to be used internally to save on
 * intermediate #XbNode allocations.
 *
 * Returns: (transfer container) (element-type XbSiloNode): results, or %NULL if unfound
 *
 * Since: 0.2.0
 **/
GPtrArray *
xb_silo_query_sn_with_root(XbSilo *self, XbNode *n, const gchar *xpath, guint limit, GError **error)
{
  return silo_query_with_root(self, n, xpath, limit, XB_SILO_QUERY_HELPER_USE_SN, error);
}

static void
_g_ptr_array_reverse(GPtrArray *array)
{
  guint last_idx = array->len - 1;
  for (guint i = 0; i < array->len / 2; i++) {
    gpointer tmp = array->pdata[i];
    array->pdata[i] = array->pdata[last_idx - i];
    array->pdata[last_idx - i] = tmp;
  }
}

/**
 * xb_silo_query_with_root_full: (skip)
 * @self: a #XbSilo
 * @n: (allow-none): a #XbNode
 * @query: an #XbQuery
 * @context: (nullable) (transfer none): context including values bound to opcodes of type
 *     %XB_OPCODE_KIND_BOUND_INTEGER or %XB_OPCODE_KIND_BOUND_TEXT, or %NULL if
 *     the query doesn’t need any context
 * @first_result_only: %TRUE if only the first result is going to be used; this
 *     overrides the limit set in @context, and may perform other optimisations
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query, returning up to @limit results.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a subset of XPath is supported.
 *
 * Returns: (transfer container) (element-type XbNode): results, or %NULL if unfound
 *
 * Since: 0.3.0
 **/
GPtrArray *
xb_silo_query_with_root_full(XbSilo *self,
           XbNode *n,
           XbQuery *query,
           XbQueryContext *context,
           gboolean first_result_only,
           GError **error)
{
  XbSiloNode *sn = NULL;
  g_autoptr(GHashTable) results_hash = g_hash_table_new(g_direct_hash, g_direct_equal);
  g_autoptr(GPtrArray) results =
      g_ptr_array_new_with_free_func((GDestroyNotify)g_object_unref);
  g_autoptr(GTimer) timer = xb_silo_start_profile(self);
  XbSiloQueryData query_data = {
      .sn = NULL,
      .position = 0,
  };
  G_GNUC_BEGIN_IGNORE_DEPRECATIONS
  XbQueryFlags query_flags = (context != NULL) ? xb_query_context_get_flags(context)
                 : xb_query_get_flags(query);
  G_GNUC_END_IGNORE_DEPRECATIONS

  /* convert the XB_OPCODE_KIND_BOUND_TEXT into a XB_OPCODE_KIND_BOUND_INDEXED_TEXT */
  if (context != NULL && query_flags & XB_QUERY_FLAG_USE_INDEXES) {
    XbValueBindings *bindings = xb_query_context_get_bindings(context);
    if (!xb_value_bindings_indexed_text_lookup(bindings, self, error))
      return NULL;
  }

  /* empty silo */
  if (xb_silo_is_empty(self)) {
    g_set_error_literal(error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND, "silo has no data");
    return NULL;
  }

  /* subtree query */
  if (n != NULL)
    sn = xb_node_get_sn(n);

  /* only one query allowed */
  if (!xb_silo_query_part(self,
        sn,
        results,
        results_hash,
        query,
        context,
        first_result_only,
        &query_data,
        XB_SILO_QUERY_HELPER_NONE,
        error))
    return NULL;

  /* profile */
  if (xb_silo_get_profile_flags(self) & XB_SILO_PROFILE_FLAG_XPATH) {
    g_autofree gchar *tmp = xb_query_to_string(query);
    g_autofree gchar *bindings_str = NULL;
    G_GNUC_BEGIN_IGNORE_DEPRECATIONS
    guint limit = first_result_only    ? 1
            : (context != NULL) ? xb_query_context_get_limit(context)
              : xb_query_get_limit(query);
    G_GNUC_END_IGNORE_DEPRECATIONS

    if (context != NULL) {
      XbValueBindings *bindings = xb_query_context_get_bindings(context);
      bindings_str = xb_value_bindings_to_string(bindings);
    }

    xb_silo_add_profile(self,
            timer,
            "query on %s with `%s` [%s] limit=%u -> %u results",
            n != NULL ? xb_node_get_element(n) : "/",
            tmp,
            bindings_str != NULL ? bindings_str : "",
            limit,
            results->len);
  }

  /* nothing found */
  if (results->len == 0) {
    if (error != NULL) {
      g_autofree gchar *tmp = xb_query_to_string(query);
      g_set_error(error,
            G_IO_ERROR,
            G_IO_ERROR_NOT_FOUND,
            "no results for XPath query '%s'",
            tmp);
    }
    return NULL;
  }

  /* reverse order */
  if (query_flags & XB_QUERY_FLAG_REVERSE)
    _g_ptr_array_reverse(results);

  return g_steal_pointer(&results);
}

/**
 * xb_silo_query_full:
 * @self: a #XbSilo
 * @query: an #XbQuery
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a subset of XPath is supported.
 *
 * Returns: (transfer container) (element-type XbNode): results, or %NULL if unfound
 *
 * Since: 0.1.13
 **/
GPtrArray *
xb_silo_query_full(XbSilo *self, XbQuery *query, GError **error)
{
  return xb_silo_query_with_context(self, query, NULL, error);
}

/**
 * xb_silo_query_with_context:
 * @self: a #XbSilo
 * @query: an #XbQuery
 * @context: (nullable) (transfer none): context including values bound to opcodes of type
 *     %XB_OPCODE_KIND_BOUND_INTEGER or %XB_OPCODE_KIND_BOUND_TEXT, or %NULL if
 *     the query doesn’t need any context
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a subset of XPath is supported.
 *
 * Returns: (transfer container) (element-type XbNode): results, or %NULL if unfound
 *
 * Since: 0.3.0
 **/
GPtrArray *
xb_silo_query_with_context(XbSilo *self, XbQuery *query, XbQueryContext *context, GError **error)
{
  g_return_val_if_fail(XB_IS_SILO(self), NULL);
  g_return_val_if_fail(XB_IS_QUERY(query), NULL);
  g_return_val_if_fail(error == NULL || *error == NULL, NULL);
  return xb_silo_query_with_root_full(self, NULL, query, context, FALSE, error);
}

/**
 * xb_silo_query_first_full:
 * @self: a #XbSilo
 * @query: an #XbQuery
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query, returning up to one result.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a tiny subset of XPath 1.0 is supported.
 *
 * Returns: (transfer full): a #XbNode, or %NULL if unfound
 *
 * Since: 0.1.13
 **/
XbNode *
xb_silo_query_first_full(XbSilo *self, XbQuery *query, GError **error)
{
  return xb_silo_query_first_with_context(self, query, NULL, error);
}

/**
 * xb_silo_query_first_with_context:
 * @self: a #XbSilo
 * @query: an #XbQuery
 * @context: (nullable) (transfer none): context including values bound to opcodes of type
 *     %XB_OPCODE_KIND_BOUND_INTEGER or %XB_OPCODE_KIND_BOUND_TEXT, or %NULL if
 *     the query doesn’t need any context
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query, returning up to one result.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a tiny subset of XPath 1.0 is supported.
 *
 * Returns: (transfer full): a #XbNode, or %NULL if unfound
 *
 * Since: 0.3.0
 **/
XbNode *
xb_silo_query_first_with_context(XbSilo *self,
         XbQuery *query,
         XbQueryContext *context,
         GError **error)
{
  g_autoptr(GPtrArray) results = NULL;

  results = xb_silo_query_with_root_full(self, NULL, query, context, TRUE, error);

  if (results == NULL)
    return NULL;
  return g_object_ref(g_ptr_array_index(results, 0));
}

/**
 * xb_silo_query:
 * @self: a #XbSilo
 * @xpath: an XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @limit: maximum number of results to return, or 0 for "all"
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query, returning up to @limit results.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a subset of XPath is supported.
 *
 * Returns: (transfer container) (element-type XbNode): results, or %NULL if unfound
 *
 * Since: 0.1.0
 **/
GPtrArray *
xb_silo_query(XbSilo *self, const gchar *xpath, guint limit, GError **error)
{
  g_return_val_if_fail(XB_IS_SILO(self), NULL);
  g_return_val_if_fail(xpath != NULL, NULL);
  g_return_val_if_fail(error == NULL || *error == NULL, NULL);
  return xb_silo_query_with_root(self, NULL, xpath, limit, error);
}

/**
 * xb_silo_query_first:
 * @self: a #XbSilo
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @error: the #GError, or %NULL
 *
 * Searches the silo using an XPath query, returning up to one result.
 *
 * It is safe to call this function from a different thread to the one that
 * created the #XbSilo.
 *
 * Please note: Only a tiny subset of XPath 1.0 is supported.
 *
 * Returns: (transfer full): a #XbNode, or %NULL if unfound
 *
 * Since: 0.1.0
 **/
XbNode *
xb_silo_query_first(XbSilo *self, const gchar *xpath, GError **error)
{
  g_autoptr(GPtrArray) results = NULL;
  results = xb_silo_query_with_root(self, NULL, xpath, 1, error);
  if (results == NULL)
    return NULL;
  return g_object_ref(g_ptr_array_index(results, 0));
}

/**
 * xb_silo_query_build_index:
 * @self: a #XbSilo
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @attr: (nullable): Attribute name, e.g. `type`, or NULL
 * @error: the #GError, or %NULL
 *
 * Adds the `attr()` or `text()` results of a query to the index.
 *
 * Returns: %TRUE for success
 *
 * Since: 0.1.4
 **/
gboolean
xb_silo_query_build_index(XbSilo *self, const gchar *xpath, const gchar *attr, GError **error)
{
  g_autoptr(GError) error_local = NULL;
  g_autoptr(GPtrArray) array = NULL;

  g_return_val_if_fail(XB_IS_SILO(self), FALSE);
  g_return_val_if_fail(xpath != NULL, FALSE);
  g_return_val_if_fail(error == NULL || *error == NULL, FALSE);

  /* do the query */
  array =
      silo_query_with_root(self, NULL, xpath, 0, XB_SILO_QUERY_HELPER_USE_SN, &error_local);
  if (array == NULL) {
    if (g_error_matches(error_local, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT) ||
        g_error_matches(error_local, G_IO_ERROR, G_IO_ERROR_NOT_FOUND)) {
      g_debug("ignoring index: %s", error_local->message);
      return TRUE;
    }
    g_propagate_error(error, g_steal_pointer(&error_local));
    return FALSE;
  }

  /* add each attribute name AND value */
  for (guint i = 0; i < array->len; i++) {
    XbSiloNode *sn = g_ptr_array_index(array, i);
    if (attr != NULL) {
      guint8 attr_count = xb_silo_node_get_attr_count(sn);
      for (guint8 j = 0; j < attr_count; j++) {
        XbSiloNodeAttr *a = xb_silo_node_get_attr(sn, j);
        if (!xb_silo_strtab_index_insert(self, a->attr_name, error))
          return FALSE;
        if (!xb_silo_strtab_index_insert(self, a->attr_value, error))
          return FALSE;
      }
    } else if (xb_silo_node_get_text_idx(sn) != XB_SILO_UNSET) {
      if (!xb_silo_strtab_index_insert(self,
               xb_silo_node_get_text_idx(sn),
               error))
        return FALSE;
    }
  }

  /* success */
  return TRUE;
}

Coverage Report

Created: 2026-05-30 06:50