githubmirror/libxmlb

src/xb-node-query.c
404 строки11 KB
Richard Hughes
trivial: Restore NULL-returning in xb_node_get_text()
06 мар 2025, 18:36
06 мар 2025, 18:3639a3b38
/*
 * Copyright 2018 Richard Hughes <richard@hughsie.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#define G_LOG_DOMAIN "XbNode"

#include "config.h"

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

#include "xb-node-query.h"
#include "xb-node-silo.h"
#include "xb-silo-export-private.h"
#include "xb-silo-query-private.h"

/**
 * xb_node_query:
 * @self: a #XbNode
 * @xpath: an XPath, e.g. `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_node_query(XbNode *self, const gchar *xpath, guint limit, GError **error)
{
	g_return_val_if_fail(XB_IS_NODE(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(xb_node_get_silo(self), self, xpath, limit, error);
}

/**
 * xb_node_query_full:
 * @self: a #XbNode
 * @query: an #XbQuery
 * @error: the #GError, or %NULL
 *
 * Searches the silo using a prepared query. To search using a query with
 * bound values, use xb_node_query_with_context().
 *
 * 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: 0.1.4
 **/
GPtrArray *
xb_node_query_full(XbNode *self, XbQuery *query, GError **error)
{
	g_return_val_if_fail(XB_IS_NODE(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(xb_node_get_silo(self),
					    self,
					    query,
					    NULL,
					    FALSE,
					    error);
}

/**
 * xb_node_query_with_context:
 * @self: 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
 * @error: the #GError, or %NULL
 *
 * Searches the silo using a prepared query, substituting values from the
 * bindings in @context for bound opcodes as needed.
 *
 * 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_node_query_with_context(XbNode *self, XbQuery *query, XbQueryContext *context, GError **error)
{
	g_return_val_if_fail(XB_IS_NODE(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(xb_node_get_silo(self),
					    self,
					    query,
					    context,
					    FALSE,
					    error);
}

/**
 * xb_node_query_first_full:
 * @self: a #XbNode
 * @query: an #XbQuery
 * @error: the #GError, or %NULL
 *
 * Searches the silo using a prepared query, returning up to one result. To
 * search using a query with bound values, use
 * xb_node_query_first_with_context().
 *
 * 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 full): a #XbNode, or %NULL if unfound
 *
 * Since: 0.1.11
 **/
XbNode *
xb_node_query_first_full(XbNode *self, XbQuery *query, GError **error)
{
	return xb_node_query_first_with_context(self, query, NULL, error);
}

/**
 * xb_node_query_first_with_context:
 * @self: 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
 * @error: the #GError, or %NULL
 *
 * Searches the silo using a prepared 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 subset of XPath is supported.
 *
 * Returns: (transfer full): a #XbNode, or %NULL if unfound
 *
 * Since: 0.3.0
 **/
XbNode *
xb_node_query_first_with_context(XbNode *self,
				 XbQuery *query,
				 XbQueryContext *context,
				 GError **error)
{
	g_autoptr(GPtrArray) results = NULL;

	g_return_val_if_fail(XB_IS_NODE(self), NULL);
	g_return_val_if_fail(XB_IS_QUERY(query), NULL);
	g_return_val_if_fail(error == NULL || *error == NULL, NULL);

	/* nodes don't have to include themselves as part of the query */
	results =
	    xb_silo_query_with_root_full(xb_node_get_silo(self), self, query, context, TRUE, error);

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

/**
 * xb_node_query_first:
 * @self: a #XbNode
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @error: the #GError, or %NULL
 *
 * Searches the node using an XPath query, returning up to one result.
 *
 * 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_node_query_first(XbNode *self, const gchar *xpath, GError **error)
{
	g_autoptr(GPtrArray) results = NULL;

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

	/* nodes don't have to include themselves as part of the query */
	results = xb_silo_query_with_root(xb_node_get_silo(self), self, xpath, 1, error);
	if (results == NULL)
		return NULL;
	return g_object_ref(g_ptr_array_index(results, 0));
}

/**
 * xb_node_query_text:
 * @self: a #XbNode
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @error: the #GError, or %NULL
 *
 * Searches the node 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 subset of XPath is supported.
 *
 * Returns: (transfer none): a string, or %NULL if unfound
 *
 * Since: 0.1.0
 **/
const gchar *
xb_node_query_text(XbNode *self, const gchar *xpath, GError **error)
{
	XbSilo *silo;
	g_autoptr(GPtrArray) results = NULL;
	XbSiloNode *sn;

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

	silo = xb_node_get_silo(self);
	results = xb_silo_query_sn_with_root(silo, self, xpath, 1, error);
	if (results == NULL)
		return NULL;
	sn = g_ptr_array_index(results, 0);
	if (xb_silo_node_get_text_idx(sn) == XB_SILO_UNSET) {
		g_set_error_literal(error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND, "no text data");
		return NULL;
	}
	return xb_silo_from_strtab(silo, xb_silo_node_get_text_idx(sn), error);
}

/**
 * xb_node_query_attr:
 * @self: a #XbNode
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @name: an attribute name, e.g. `type`
 * @error: the #GError, or %NULL
 *
 * Searches the node 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 subset of XPath is supported.
 *
 * Returns: (transfer none): a string, or %NULL if unfound
 *
 * Since: 0.1.0
 **/
const gchar *
xb_node_query_attr(XbNode *self, const gchar *xpath, const gchar *name, GError **error)
{
	XbSiloNodeAttr *a;
	XbSilo *silo;
	g_autoptr(GPtrArray) results = NULL;
	XbSiloNode *sn;

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

	silo = xb_node_get_silo(self);
	results = xb_silo_query_sn_with_root(silo, self, xpath, 1, error);
	if (results == NULL)
		return NULL;
	sn = g_ptr_array_index(results, 0);

	a = xb_silo_get_node_attr_by_str(silo, sn, name);
	if (a == NULL) {
		g_set_error_literal(error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND, "no text data");
		return NULL;
	}
	return xb_silo_from_strtab(silo, a->attr_value, error);
}

/**
 * xb_node_query_export:
 * @self: a #XbNode
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @error: the #GError, or %NULL
 *
 * Searches the node using an XPath query, returning an XML string of the
 * result and any children.
 *
 * 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 none): a string, or %NULL if unfound
 *
 * Since: 0.1.0
 **/
gchar *
xb_node_query_export(XbNode *self, const gchar *xpath, GError **error)
{
	GString *xml;
	XbSilo *silo;
	g_autoptr(GPtrArray) results = NULL;
	XbSiloNode *sn;

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

	silo = xb_node_get_silo(self);
	results = xb_silo_query_sn_with_root(silo, self, xpath, 1, error);
	if (results == NULL)
		return NULL;
	sn = g_ptr_array_index(results, 0);

	xml = xb_silo_export_with_root(silo, sn, XB_NODE_EXPORT_FLAG_NONE, error);
	if (xml == NULL)
		return NULL;
	return g_string_free(xml, FALSE);
}

/**
 * xb_node_query_text_as_uint:
 * @self: a #XbNode
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @error: the #GError, or %NULL
 *
 * Searches the node 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 subset of XPath is supported.
 *
 * Returns: a #guint64, or %G_MAXUINT64 if unfound
 *
 * Since: 0.1.0
 **/
guint64
xb_node_query_text_as_uint(XbNode *self, const gchar *xpath, GError **error)
{
	const gchar *tmp;

	g_return_val_if_fail(XB_IS_NODE(self), G_MAXUINT64);
	g_return_val_if_fail(xpath != NULL, G_MAXUINT64);
	g_return_val_if_fail(error == NULL || *error == NULL, G_MAXUINT64);

	tmp = xb_node_query_text(self, xpath, error);
	if (tmp == NULL)
		return G_MAXUINT64;

	if (g_str_has_prefix(tmp, "0x"))
		return g_ascii_strtoull(tmp + 2, NULL, 16);
	return g_ascii_strtoull(tmp, NULL, 10);
}

/**
 * xb_node_query_attr_as_uint:
 * @self: a #XbNode
 * @xpath: An XPath, e.g. `/components/component[@type=desktop]/id[abe.desktop]`
 * @name: an attribute name, e.g. `type`
 * @error: the #GError, or %NULL
 *
 * Searches the node 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 subset of XPath is supported.
 *
 * Returns: a #guint64, or %G_MAXUINT64 if unfound
 *
 * Since: 0.1.0
 **/
guint64
xb_node_query_attr_as_uint(XbNode *self, const gchar *xpath, const gchar *name, GError **error)
{
	const gchar *tmp;

	g_return_val_if_fail(XB_IS_NODE(self), G_MAXUINT64);
	g_return_val_if_fail(xpath != NULL, G_MAXUINT64);
	g_return_val_if_fail(error == NULL || *error == NULL, G_MAXUINT64);

	tmp = xb_node_query_attr(self, xpath, name, error);
	if (tmp == NULL)
		return G_MAXUINT64;

	if (g_str_has_prefix(tmp, "0x"))
		return g_ascii_strtoull(tmp + 2, NULL, 16);
	return g_ascii_strtoull(tmp, NULL, 10);
}