1 files changed, 368 insertions, 0 deletions
diff --git a/src/libknot/rdataset.c b/src/libknot/rdataset.c
new file mode 100644
index 0000000..4767bf9
--- /dev/null
+++ b/src/libknot/rdataset.c
@@ -0,0 +1,368 @@
+/*  Copyright (C) 2018 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 <assert.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "libknot/attribute.h"
+#include "libknot/rdataset.h"
+#include "libknot/errcode.h"
+#include "contrib/mempattern.h"
+
+static knot_rdata_t *rr_seek(const knot_rdataset_t *rrs, uint16_t pos)
+{
+	assert(rrs);
+	assert(0 < rrs->count);
+	assert(pos < rrs->count);
+
+	uint8_t *raw = (uint8_t *)(rrs->rdata);
+	for (uint16_t i = 0; i < pos; ++i) {
+		raw += knot_rdata_size(((knot_rdata_t *)raw)->len);
+	}
+
+	return (knot_rdata_t *)raw;
+}
+
+static int find_rr_pos(const knot_rdataset_t *rrs, const knot_rdata_t *rr)
+{
+	knot_rdata_t *search_rr = rrs->rdata;
+	for (uint16_t i = 0; i < rrs->count; ++i) {
+		if (knot_rdata_cmp(rr, search_rr) == 0) {
+			return i;
+		}
+		search_rr = knot_rdataset_next(search_rr);
+	}
+
+	return KNOT_ENOENT;
+}
+
+static int add_rr_at(knot_rdataset_t *rrs, const knot_rdata_t *rr, uint16_t pos,
+                     knot_mm_t *mm)
+{
+	assert(rrs);
+	assert(rr);
+	assert(pos <= rrs->count);
+
+	if (rrs->count == UINT16_MAX) {
+		return KNOT_ESPACE;
+	}
+
+	size_t total_size = knot_rdataset_size(rrs);
+	size_t new_size = knot_rdata_size(rr->len);
+
+	// Realloc RDATA.
+	knot_rdata_t *tmp = mm_realloc(mm, rrs->rdata, total_size + new_size,
+	                               total_size);
+	if (tmp == NULL) {
+		return KNOT_ENOMEM;
+	} else {
+		rrs->rdata = tmp;
+	}
+
+	if (rrs->count == 0 || pos == rrs->count) {
+		// No need to rearange RDATA.
+		rrs->count++;
+		knot_rdata_t *new_rr = rr_seek(rrs, pos);
+		knot_rdata_init(new_rr, rr->len, rr->data);
+		return KNOT_EOK;
+	}
+
+	// RDATA have to be rearanged.
+	knot_rdata_t *old_rr = rr_seek(rrs, pos);
+	knot_rdata_t *last_rr = rr_seek(rrs, rrs->count - 1);
+
+	// Make space for new RDATA by moving the array.
+	uint8_t *dst = (uint8_t *)old_rr + new_size;
+	assert(old_rr <= last_rr);
+	size_t len = ((uint8_t *)last_rr - (uint8_t *)old_rr) +
+	             knot_rdata_size(last_rr->len);
+	memmove(dst, old_rr, len);
+
+	// Set new RDATA.
+	knot_rdata_init(old_rr, rr->len, rr->data);
+	rrs->count++;
+
+	return KNOT_EOK;
+}
+
+static int remove_rr_at(knot_rdataset_t *rrs, uint16_t pos, knot_mm_t *mm)
+{
+	assert(rrs);
+	assert(0 < rrs->count);
+	assert(pos < rrs->count);
+
+	knot_rdata_t *old_rr = rr_seek(rrs, pos);
+	knot_rdata_t *last_rr = rr_seek(rrs, rrs->count - 1);
+
+	size_t total_size = knot_rdataset_size(rrs);
+	size_t old_size = knot_rdata_size(old_rr->len);
+
+	// Move RDATA.
+	uint8_t *old_threshold = (uint8_t *)old_rr + old_size;
+	uint8_t *last_threshold = (uint8_t *)last_rr + knot_rdata_size(last_rr->len);
+	assert(old_threshold <= last_threshold);
+	memmove(old_rr, old_threshold, last_threshold - old_threshold);
+
+	if (rrs->count > 1) {
+		// Realloc RDATA.
+		knot_rdata_t *tmp = mm_realloc(mm, rrs->rdata, total_size - old_size,
+		                               total_size);
+		if (tmp == NULL) {
+			return KNOT_ENOMEM;
+		} else {
+			rrs->rdata = tmp;
+		}
+	} else {
+		// Free RDATA.
+		mm_free(mm, rrs->rdata);
+		rrs->rdata = NULL;
+	}
+	rrs->count--;
+
+	return KNOT_EOK;
+}
+
+_public_
+void knot_rdataset_clear(knot_rdataset_t *rrs, knot_mm_t *mm)
+{
+	if (rrs == NULL) {
+		return;
+	}
+
+	mm_free(mm, rrs->rdata);
+	knot_rdataset_init(rrs);
+}
+
+_public_
+int knot_rdataset_copy(knot_rdataset_t *dst, const knot_rdataset_t *src, knot_mm_t *mm)
+{
+	if (dst == NULL || src == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	dst->count = src->count;
+	size_t src_size = knot_rdataset_size(src);
+	dst->rdata = mm_alloc(mm, src_size);
+	if (dst->rdata == NULL) {
+		return KNOT_ENOMEM;
+	}
+
+	memcpy(dst->rdata, src->rdata, src_size);
+
+	return KNOT_EOK;
+}
+
+_public_
+knot_rdata_t *knot_rdataset_at(const knot_rdataset_t *rrs, uint16_t pos)
+{
+	if (rrs == NULL || rrs->count == 0 || pos >= rrs->count) {
+		return NULL;
+	}
+
+	return rr_seek(rrs, pos);
+}
+
+_public_
+size_t knot_rdataset_size(const knot_rdataset_t *rrs)
+{
+	if (rrs == NULL || rrs->count == 0) {
+		return 0;
+	}
+
+	const knot_rdata_t *last = rr_seek(rrs, rrs->count - 1);
+	return (uint8_t *)last + knot_rdata_size(last->len) - (uint8_t *)rrs->rdata;
+}
+
+_public_
+int knot_rdataset_add(knot_rdataset_t *rrs, const knot_rdata_t *rr, knot_mm_t *mm)
+{
+	if (rrs == NULL || rr == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	// First insert to empty rdataset.
+	if (rrs->count == 0) {
+		return add_rr_at(rrs, rr, 0, mm);
+	}
+
+	for (int i = rrs->count - 1; i >= 0; --i) {
+		const knot_rdata_t *rrset_rr = rr_seek(rrs, i);
+		int cmp = knot_rdata_cmp(rrset_rr, rr);
+		if (cmp == 0) {
+			// Duplicate - no need to add this RR.
+			return KNOT_EOK;
+		} else if (cmp < 0) {
+			// Found position to insert.
+			return add_rr_at(rrs, rr, i + 1, mm);
+		}
+	}
+
+	// If flow gets here, it means that we should insert at the first position.
+	return add_rr_at(rrs, rr, 0, mm);
+}
+
+_public_
+int knot_rdataset_reserve(knot_rdataset_t *rrs, uint16_t size, knot_mm_t *mm)
+{
+	if (rrs == NULL) {
+		return KNOT_EINVAL;
+	} else if (rrs->count == UINT16_MAX) {
+		return KNOT_ESPACE;
+	}
+
+	size_t old_size = knot_rdataset_size(rrs);
+	size_t new_size = old_size + knot_rdata_size(size);
+
+	knot_rdata_t *tmp = mm_realloc(mm, rrs->rdata, new_size, old_size);
+	if (tmp == NULL) {
+		return KNOT_ENOMEM;
+	}
+	rrs->rdata = tmp;
+	rrs->count++;
+
+	// We have to initialise the 'size' field in the reserved space.
+	rr_seek(rrs, rrs->count - 1)->len = size;
+
+	return KNOT_EOK;
+}
+
+_public_
+int knot_rdataset_unreserve(knot_rdataset_t *rrs, knot_mm_t *mm)
+{
+	if (rrs == NULL || rrs->count == 0) {
+		return KNOT_EINVAL;
+	}
+
+	return remove_rr_at(rrs, rrs->count - 1, mm);
+}
+
+_public_
+bool knot_rdataset_eq(const knot_rdataset_t *rrs1, const knot_rdataset_t *rrs2)
+{
+	if (rrs1 == NULL || rrs2 == NULL || rrs1->count != rrs2->count) {
+		return false;
+	}
+
+	knot_rdata_t *rr1 = rrs1->rdata;
+	knot_rdata_t *rr2 = rrs2->rdata;
+	for (uint16_t i = 0; i < rrs1->count; ++i) {
+		if (knot_rdata_cmp(rr1, rr2) != 0) {
+			return false;
+		}
+		rr1 = knot_rdataset_next(rr1);
+		rr2 = knot_rdataset_next(rr2);
+	}
+
+	return true;
+}
+
+_public_
+bool knot_rdataset_member(const knot_rdataset_t *rrs, const knot_rdata_t *rr)
+{
+	if (rrs == NULL) {
+		return false;
+	}
+
+	knot_rdata_t *cmp_rr = rrs->rdata;
+	for (uint16_t i = 0; i < rrs->count; ++i) {
+		int cmp = knot_rdata_cmp(cmp_rr, rr);
+		if (cmp == 0) {
+			// Match.
+			return true;
+		} else if (cmp > 0) {
+			// 'Greater' RR present, no need to continue.
+			return false;
+		}
+		cmp_rr = knot_rdataset_next(cmp_rr);
+	}
+
+	return false;
+}
+
+_public_
+int knot_rdataset_merge(knot_rdataset_t *rrs1, const knot_rdataset_t *rrs2,
+                        knot_mm_t *mm)
+{
+	if (rrs1 == NULL || rrs2 == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	knot_rdata_t *rr2 = rrs2->rdata;
+	for (uint16_t i = 0; i < rrs2->count; ++i) {
+		int ret = knot_rdataset_add(rrs1, rr2, mm);
+		if (ret != KNOT_EOK) {
+			return ret;
+		}
+		rr2 = knot_rdataset_next(rr2);
+	}
+
+	return KNOT_EOK;
+}
+
+_public_
+int knot_rdataset_intersect(const knot_rdataset_t *rrs1, const knot_rdataset_t *rrs2,
+                            knot_rdataset_t *out, knot_mm_t *mm)
+{
+	if (rrs1 == NULL || rrs2 == NULL || out == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	knot_rdataset_init(out);
+	knot_rdata_t *rr1 = rrs1->rdata;
+	for (uint16_t i = 0; i < rrs1->count; ++i) {
+		if (knot_rdataset_member(rrs2, rr1)) {
+			// Add RR into output intersection RRSet.
+			int ret = knot_rdataset_add(out, rr1, mm);
+			if (ret != KNOT_EOK) {
+				knot_rdataset_clear(out, mm);
+				return ret;
+			}
+		}
+		rr1 = knot_rdataset_next(rr1);
+	}
+
+	return KNOT_EOK;
+}
+
+_public_
+int knot_rdataset_subtract(knot_rdataset_t *from, const knot_rdataset_t *what,
+                           knot_mm_t *mm)
+{
+	if (from == NULL || what == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	if (from->rdata == what->rdata) {
+		knot_rdataset_clear(from, mm);
+		knot_rdataset_init((knot_rdataset_t *) what);
+		return KNOT_EOK;
+	}
+
+	knot_rdata_t *to_remove = what->rdata;
+	for (uint16_t i = 0; i < what->count; ++i) {
+		int pos_to_remove = find_rr_pos(from, to_remove);
+		if (pos_to_remove >= 0) {
+			int ret = remove_rr_at(from, pos_to_remove, mm);
+			if (ret != KNOT_EOK) {
+				return ret;
+			}
+		}
+		to_remove = knot_rdataset_next(to_remove);
+	}
+
+	return KNOT_EOK;
+}