utils: add general lookup container

src/utils/common/lookup.c

+/*  Copyright (C) 2016 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <string.h>
+
+#include "utils/common/lookup.h"
+#include "contrib/mempattern.h"
+#include "contrib/ucw/mempool.h"
+#include "libknot/error.h"
+
+int lookup_init(lookup_t *lookup)
+{
+	if (lookup == NULL) {
+		return KNOT_EINVAL;
+	}
+	memset(lookup, 0, sizeof(*lookup));
+
+	mm_ctx_mempool(&lookup->mm, MM_DEFAULT_BLKSIZE);
+	lookup->trie = hattrie_create_n(TRIE_BUCKET_SIZE, &lookup->mm);
+	if (lookup->trie == NULL) {
+		mp_delete(lookup->mm.ctx);
+		return KNOT_ENOMEM;
+	}
+
+	return KNOT_EOK;
+}
+
+static void reset_output(lookup_t *lookup)
+{
+	if (lookup == NULL) {
+		return;
+	}
+
+	mm_free(&lookup->mm, lookup->found.key);
+	lookup->found.key = NULL;
+	lookup->found.data = NULL;
+
+	lookup->iter.count = 0;
+
+	mm_free(&lookup->mm, lookup->iter.first_key);
+	lookup->iter.first_key = NULL;
+
+	hattrie_iter_free(lookup->iter.it);
+	lookup->iter.it = NULL;
+}
+
+void lookup_deinit(lookup_t *lookup)
+{
+	if (lookup == NULL) {
+		return;
+	}
+
+	reset_output(lookup);
+
+	hattrie_free(lookup->trie);
+	mp_delete(lookup->mm.ctx);
+}
+
+int lookup_insert(lookup_t *lookup, const char *str, void *data)
+{
+	if (lookup == NULL || str == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	size_t str_len = strlen(str);
+	if (str_len == 0) {
+		return KNOT_EINVAL;
+	}
+
+	value_t *val = hattrie_get(lookup->trie, str, str_len);
+	if (val == NULL) {
+		return KNOT_ENOMEM;
+	}
+	*val = data;
+
+	return KNOT_EOK;
+}
+
+void lookup_index(lookup_t *lookup)
+{
+	if (lookup == NULL) {
+		return;
+	}
+
+	hattrie_build_index(lookup->trie);
+}
+
+static int set_key(lookup_t *lookup, char **dst, const char *key, size_t key_len)
+{
+	if (*dst != NULL) {
+		mm_free(&lookup->mm, *dst);
+	}
+	*dst = mm_alloc(&lookup->mm, key_len + 1);
+	if (*dst == NULL) {
+		return KNOT_ENOMEM;
+	}
+	memcpy(*dst, key, key_len);
+	(*dst)[key_len] = '\0';
+
+	return KNOT_EOK;
+}
+
+int lookup_search(lookup_t *lookup, const char *str, size_t str_len)
+{
+	if (lookup == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	// Change NULL string to the empty one.
+	if (str == NULL) {
+		str = "";
+	}
+
+	reset_output(lookup);
+
+	size_t new_len = 0;
+	hattrie_iter_t *it = hattrie_iter_begin(lookup->trie, true);
+	for (; !hattrie_iter_finished(it); hattrie_iter_next(it)) {
+		size_t len;
+		const char *key = hattrie_iter_key(it, &len);
+
+		// Compare with a shorter key.
+		if (len < str_len) {
+			int ret = memcmp(str, key, len);
+			if (ret >= 0) {
+				continue;
+			} else {
+				break;
+			}
+		}
+
+		// Compare with an equal length or longer key.
+		int ret = memcmp(str, key, str_len);
+		if (ret == 0) {
+			lookup->iter.count++;
+
+			// First candidate.
+			if (lookup->iter.count == 1) {
+				ret = set_key(lookup, &lookup->found.key, key, len);
+				if (ret != KNOT_EOK) {
+					break;
+				}
+				lookup->found.data = *hattrie_iter_val(it);
+				new_len = len;
+			// Another candidate.
+			} else if (new_len > str_len) {
+				if (new_len > len) {
+					new_len = len;
+				}
+				while (memcmp(lookup->found.key, key, new_len) != 0) {
+					new_len--;
+				}
+			}
+		// Stop if greater than the key, and also than all the following keys.
+		} else if (ret < 0) {
+			break;
+		}
+	}
+	hattrie_iter_free(it);
+
+	switch (lookup->iter.count) {
+	case 0:
+		return KNOT_ENOENT;
+	case 1:
+		return KNOT_EOK;
+	default:
+		// Store full name of the first candidate.
+		if (set_key(lookup, &lookup->iter.first_key, lookup->found.key,
+		            strlen(lookup->found.key)) != KNOT_EOK) {
+			return KNOT_ENOMEM;
+		}
+		lookup->found.key[new_len] = '\0';
+		lookup->found.data = NULL;
+
+		return KNOT_EFEWDATA;
+	}
+}
+
+void lookup_list(lookup_t *lookup)
+{
+	if (lookup == NULL || lookup->iter.first_key == NULL) {
+		return;
+	}
+
+	if (lookup->iter.it != NULL) {
+		if (hattrie_iter_finished(lookup->iter.it)) {
+			hattrie_iter_free(lookup->iter.it);
+			lookup->iter.it = NULL;
+			return;
+		}
+
+		hattrie_iter_next(lookup->iter.it);
+
+		size_t len;
+		const char *key = hattrie_iter_key(lookup->iter.it, &len);
+
+		int ret = set_key(lookup, &lookup->found.key, key, len);
+		if (ret == KNOT_EOK) {
+			lookup->found.data = *hattrie_iter_val(lookup->iter.it);
+		}
+		return;
+	}
+
+	lookup->iter.it = hattrie_iter_begin(lookup->trie, true);
+	while (!hattrie_iter_finished(lookup->iter.it)) {
+		size_t len;
+		const char *key = hattrie_iter_key(lookup->iter.it, &len);
+
+		if (strcmp(key, lookup->iter.first_key) == 0) {
+			int ret = set_key(lookup, &lookup->found.key, key, len);
+			if (ret == KNOT_EOK) {
+				lookup->found.data = *hattrie_iter_val(lookup->iter.it);
+			}
+			break;
+		}
+		hattrie_iter_next(lookup->iter.it);
+	}
+}
+
+static void print_options(lookup_t *lookup, EditLine *el)
+{
+	// Get terminal lines.
+	unsigned lines = 0;
+	if (el_get(el, EL_GETTC, "li", &lines) != 0 || lines < 3) {
+		return;
+	}
+
+	for (size_t i = 1; i <= lookup->iter.count; i++) {
+		lookup_list(lookup);
+		printf("\n%s", lookup->found.key);
+
+		if (i > 1 && i % (lines - 1) == 0 && i < lookup->iter.count) {
+			printf("\n Display next from %zu possibilities? (y or n)",
+			       lookup->iter.count);
+			char next;
+			el_getc(el, &next);
+			if (next != 'y') {
+				break;
+			}
+		}
+	}
+
+	printf("\n");
+	fflush(stdout);
+}
+
+void lookup_complete(lookup_t *lookup, const char *str, size_t str_len,
+                     EditLine *el, bool add_space)
+{
+	if (lookup == NULL || el == NULL) {
+		return;
+	}
+
+	// Try to complete the command name.
+	int ret = lookup_search(lookup, str, str_len);
+	switch (ret) {
+	case KNOT_EOK:
+		el_deletestr(el, str_len);
+		el_insertstr(el, lookup->found.key);
+		if (add_space) {
+			el_insertstr(el, " ");
+		}
+		break;
+	case KNOT_EFEWDATA:
+		if (strlen(lookup->found.key) > str_len) {
+			el_deletestr(el, str_len);
+			el_insertstr(el, lookup->found.key);
+		} else {
+			print_options(lookup, el);
+		}
+		break;
+	default:
+		break;
+	}
+}

src/utils/common/lookup.h

+/*  Copyright (C) 2016 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/*!
+ * \file
+ *
+ * \brief Lookup container for textual strings.
+ *
+ * \addtogroup knot_utils
+ * @{
+ */
+
+#pragma once
+
+#include <histedit.h>
+
+#include "libknot/mm_ctx.h"
+#include "contrib/hat-trie/hat-trie.h"
+
+/*! Lookup context. */
+typedef struct {
+	/*! Memory pool context. */
+	knot_mm_t mm;
+	/*! Main hat-trie storage. */
+	hattrie_t *trie;
+
+	/*! Current (iteration) data context. */
+	struct {
+		/*! Stored key. */
+		char *key;
+		/*! Corresponding key data. */
+		void *data;
+	} found;
+
+	/*! Iteration context. */
+	struct {
+		/*! Total number of possibilies. */
+		size_t count;
+		/*! The first possibility. */
+		char *first_key;
+		/*! Hat-trie iterator. */
+		hattrie_iter_t *it;
+	} iter;
+} lookup_t;
+
+/*!
+ * Initializes the lookup context.
+ *
+ * \param[in] lookup  Lookup context.
+ *
+ * \return Error code, KNOT_EOK if successful.
+ */
+int lookup_init(lookup_t *lookup);
+
+/*!
+ * Deinitializes the lookup context.
+ *
+ * \param[in] lookup  Lookup context.
+ */
+void lookup_deinit(lookup_t *lookup);
+
+/*!
+ * Inserts given key and data into the lookup.
+ *
+ * \param[in] lookup  Lookup context.
+ * \param[in] str     Textual key.
+ * \param[in] data    Key textual data.
+ *
+ * \return Error code, KNOT_EOK if successful.
+ */
+int lookup_insert(lookup_t *lookup, const char *str, void *data);
+
+/*!
+ * Indexes the lookup container.
+ *
+ * \param[in] lookup  Lookup context.
+ */
+void lookup_index(lookup_t *lookup);
+
+/*!
+ * Searches the lookup container for the given key.
+ *
+ * \note If one candidate, lookup.found contains the key/data,
+ *       if more candidates, lookup.found contains the common key prefix and
+ *       lookup.iter.first_key is the first candidate key.
+ *
+ * \param[in] lookup   Lookup context.
+ * \param[in] str      Textual key.
+ * \param[in] str_len  Textual key length.
+ *
+ * \return Error code, KNOT_EOK if 1 candidate, KNOT_ENOENT if no candidate,
+ *         and KNOT_EFEWDATA if more candidates are possible.
+ */
+int lookup_search(lookup_t *lookup, const char *str, size_t str_len);
+
+/*!
+ * Moves the lookup iterator to the next key candidate.
+ *
+ * \note lookup.found is updated.
+ *
+ * \param[in] lookup   Lookup context.
+ */
+void lookup_list(lookup_t *lookup);
+
+/*!
+ * Completes the string based on the lookup content or prints all candidates.
+ *
+ * \param[in] lookup     Lookup context.
+ * \param[in] str        Textual key.
+ * \param[in] str_len    Textual key length.
+ * \param[in] el         Editline context.
+ * \param[in] add_space  Add one space after completed string flag.
+ */
+void lookup_complete(lookup_t *lookup, const char *str, size_t str_len,
+                     EditLine *el, bool add_space);
+
+/*! @} */

tests/.gitignore

@@ -59,3 +59,4 @@ zone_timers
 zone_update
 zonedb
 ztree
+utils/test_lookup

tests/Makefile.am

@@ -64,7 +64,13 @@ check_PROGRAMS = \
 	ztree
 
 check_PROGRAMS += \
-	modules/online_sign
+	modules/online_sign		\
+	utils/test_lookup
+
+utils_test_lookup_LDADD = \
+	$(top_builddir)/libtap/libtap.la \
+	$(top_builddir)/src/libknotus.la \
+	$(libedit_LIBS)
 
 check-compile: $(check_PROGRAMS)
 

tests/utils/test_lookup.c

+/*  Copyright (C) 2016 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <tap/basic.h>
+
+#include "libknot/error.h"
+#include "utils/common/lookup.h"
+
+static void check_search_ok(lookup_t *l, const char *in, const char *out)
+{
+	diag("Search for '%s'", in);
+	int ret = lookup_search(l, in, strlen(in));
+	ok(ret == KNOT_EOK, "Check found");
+	ok(strcmp(out, l->found.key) == 0, "Compare key");
+	ok(strcmp(out, l->found.data) == 0, "Compare data");
+	ok(l->iter.first_key == NULL, "Compare no first key");
+	ok(l->iter.count == 1, "Compare 1 count");
+}
+
+static void check_search_multi(lookup_t *l, const char *in, const char *out,
+                               const char *first, size_t count)
+{
+	diag("Search for '%s'", in);
+	int ret = lookup_search(l, in, strlen(in));
+	ok(ret == KNOT_EFEWDATA, "Check found multi");
+	ok(strcmp(out, l->found.key) == 0, "Compare key");
+	ok(l->found.data == NULL, "Compare no data");
+	ok(strcmp(first, l->iter.first_key) == 0, "Compare first key");
+	ok(l->iter.count == count, "Compare count");
+}
+
+static void check_search_none(lookup_t *l, const char *in)
+{
+	diag("Search for '%s'", in);
+	int ret = lookup_search(l, in, strlen(in));
+	ok(ret == KNOT_ENOENT, "Check not found");
+	ok(l->found.key == NULL, "Check no key");
+	ok(l->found.data == NULL, "Check no data");
+}
+
+static void init(lookup_t *l, const char **table)
+{
+	int ret = lookup_init(l);
+	ok(ret == KNOT_EOK, "Init");
+
+	while (*table != NULL) {
+		ret = lookup_insert(l, *table, (void *)*table);
+		ok(ret == KNOT_EOK, "Insert '%s'", *table);
+		table++;
+	}
+
+	lookup_index(l);
+}
+
+static void test_search_basic(void)
+{
+	const char* table[] = {
+		"aa",
+		"bb",
+		NULL
+	};
+
+	lookup_t l;
+	init(&l, table);
+
+	check_search_ok(&l, "a",  "aa");
+	check_search_ok(&l, "aa", "aa");
+	check_search_ok(&l, "b",  "bb");
+	check_search_ok(&l, "bb", "bb");
+
+	check_search_none(&l, "0");
+	check_search_none(&l, "000");
+	check_search_none(&l, "00000000000000000000000000000000000000000000");
+	check_search_none(&l, "a0");
+	check_search_none(&l, "ab");
+	check_search_none(&l, "aaa");
+	check_search_none(&l, "bbb");
+	check_search_none(&l, "cc");
+	check_search_none(&l, "ccc");
+	check_search_none(&l, "cccccccccccccccccccccccccccccccccccccccccccc");
+
+	check_search_multi(&l, "", "", "aa", 2);
+
+	lookup_deinit(&l);
+}
+
+static void test_search_iter(void)
+{
+	const char* table[] = {
+		"0",
+		"ab",
+		"abc",
+		"abcd",
+		"abc-1",
+		"abc-99",
+		"z",
+		NULL
+	};
+
+	lookup_t l;
+	init(&l, table);
+
+	check_search_multi(&l, "",     "",     "0",     7);
+	check_search_multi(&l, "a",    "ab",   "ab",    5);
+	check_search_multi(&l, "ab",   "ab",   "ab",    5);
+	check_search_multi(&l, "abc",  "abc",  "abc",   4);
+	check_search_multi(&l, "abc-", "abc-", "abc-1", 2);
+
+	lookup_deinit(&l);
+}
+
+int main(int argc, char *argv[])
+{
+	plan_lazy();
+
+	diag("Search tests basic");
+	test_search_basic();
+
+	diag("Search tests multi-result");
+	test_search_iter();
+
+	return 0;
+}