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-rw-r--r--lib/generic/README.rst62
-rw-r--r--lib/generic/array.h154
-rw-r--r--lib/generic/lru.c250
-rw-r--r--lib/generic/lru.h241
-rw-r--r--lib/generic/map.c355
-rw-r--r--lib/generic/map.h116
-rw-r--r--lib/generic/map.spdx10
-rw-r--r--lib/generic/pack.h237
-rw-r--r--lib/generic/queue.c112
-rw-r--r--lib/generic/queue.h252
-rw-r--r--lib/generic/set.h93
-rw-r--r--lib/generic/test_array.c99
-rw-r--r--lib/generic/test_lru.c111
-rw-r--r--lib/generic/test_map.c119
-rw-r--r--lib/generic/test_pack.c70
-rw-r--r--lib/generic/test_queue.c71
-rw-r--r--lib/generic/test_set.c221
-rw-r--r--lib/generic/test_trie.c154
-rw-r--r--lib/generic/trie.c900
-rw-r--r--lib/generic/trie.h139
-rw-r--r--lib/generic/trie.spdx10
21 files changed, 3776 insertions, 0 deletions
diff --git a/lib/generic/README.rst b/lib/generic/README.rst
new file mode 100644
index 0000000..e6a9994
--- /dev/null
+++ b/lib/generic/README.rst
@@ -0,0 +1,62 @@
+.. SPDX-License-Identifier: GPL-3.0-or-later
+
+Generics library
+----------------
+
+This small collection of "generics" was born out of frustration that I couldn't find no
+such thing for C. It's either bloated, has poor interface, null-checking is absent or
+doesn't allow custom allocation scheme. BSD-licensed (or compatible) code is allowed here,
+as long as it comes with a test case in `tests/test_generics.c`.
+
+* array_ - a set of simple macros to make working with dynamic arrays easier.
+* queue_ - a FIFO + LIFO queue.
+* map_ - a `Crit-bit tree`_ key-value map implementation (public domain) that comes with tests.
+* set_ - set abstraction implemented on top of ``map`` (unused now).
+* pack_ - length-prefixed list of objects (i.e. array-list).
+* lru_ - LRU-like hash table
+* trie_ - a trie-based key-value map, taken from knot-dns
+
+array
+~~~~~
+
+.. doxygenfile:: array.h
+ :project: libkres
+
+queue
+~~~~~
+
+.. doxygenfile:: queue.h
+ :project: libkres
+
+map
+~~~
+
+.. doxygenfile:: map.h
+ :project: libkres
+
+set
+~~~
+
+.. doxygenfile:: set.h
+ :project: libkres
+
+pack
+~~~~
+
+.. doxygenfile:: pack.h
+ :project: libkres
+
+lru
+~~~
+
+.. doxygenfile:: lru.h
+ :project: libkres
+
+trie
+~~~~
+
+.. doxygenfile:: trie.h
+ :project: libkres
+
+
+.. _`Crit-bit tree`: https://cr.yp.to/critbit.html
diff --git a/lib/generic/array.h b/lib/generic/array.h
new file mode 100644
index 0000000..b20a802
--- /dev/null
+++ b/lib/generic/array.h
@@ -0,0 +1,154 @@
+/* Copyright (C) 2015-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/**
+ *
+ * @file array.h
+ * @brief A set of simple macros to make working with dynamic arrays easier.
+ *
+ * @note The C has no generics, so it is implemented mostly using macros.
+ * Be aware of that, as direct usage of the macros in the evaluating macros
+ * may lead to different expectations:
+ *
+ * @code{.c}
+ * MIN(array_push(arr, val), other)
+ * @endcode
+ *
+ * May evaluate the code twice, leading to unexpected behaviour.
+ * This is a price to pay for the absence of proper generics.
+ *
+ * # Example usage:
+ *
+ * @code{.c}
+ * array_t(const char*) arr;
+ * array_init(arr);
+ *
+ * // Reserve memory in advance
+ * if (array_reserve(arr, 2) < 0) {
+ * return ENOMEM;
+ * }
+ *
+ * // Already reserved, cannot fail
+ * array_push(arr, "princess");
+ * array_push(arr, "leia");
+ *
+ * // Not reserved, may fail
+ * if (array_push(arr, "han") < 0) {
+ * return ENOMEM;
+ * }
+ *
+ * // It does not hide what it really is
+ * for (size_t i = 0; i < arr.len; ++i) {
+ * printf("%s\n", arr.at[i]);
+ * }
+ *
+ * // Random delete
+ * array_del(arr, 0);
+ * @endcode
+ * \addtogroup generics
+ * @{
+ */
+
+#pragma once
+#include <stdlib.h>
+
+/** Simplified Qt containers growth strategy. */
+static inline size_t array_next_count(size_t want)
+{
+ if (want < 2048) {
+ return (want < 20) ? want + 4 : want * 2;
+ } else {
+ return want + 2048;
+ }
+}
+
+/** @internal Incremental memory reservation */
+static inline int array_std_reserve(void *baton, void **mem, size_t elm_size, size_t want, size_t *have)
+{
+ if (*have >= want) {
+ return 0;
+ }
+ /* Simplified Qt containers growth strategy */
+ size_t next_size = array_next_count(want);
+ void *mem_new = realloc(*mem, next_size * elm_size);
+ if (mem_new != NULL) {
+ *mem = mem_new;
+ *have = next_size;
+ return 0;
+ }
+ return -1;
+}
+
+/** @internal Wrapper for stdlib free. */
+static inline void array_std_free(void *baton, void *p)
+{
+ free(p);
+}
+
+/** Declare an array structure. */
+#define array_t(type) struct {type * at; size_t len; size_t cap; }
+
+/** Zero-initialize the array. */
+#define array_init(array) ((array).at = NULL, (array).len = (array).cap = 0)
+
+/** Free and zero-initialize the array (plain malloc/free). */
+#define array_clear(array) \
+ array_clear_mm(array, array_std_free, NULL)
+
+/** Make the array empty and free pointed-to memory.
+ * Mempool usage: pass mm_free and a knot_mm_t* . */
+#define array_clear_mm(array, free, baton) \
+ (free)((baton), (array).at), array_init(array)
+
+/** Reserve capacity for at least n elements.
+ * @return 0 if success, <0 on failure */
+#define array_reserve(array, n) \
+ array_reserve_mm(array, n, array_std_reserve, NULL)
+
+/** Reserve capacity for at least n elements.
+ * Mempool usage: pass kr_memreserve and a knot_mm_t* .
+ * @return 0 if success, <0 on failure */
+#define array_reserve_mm(array, n, reserve, baton) \
+ (reserve)((baton), (void **) &(array).at, sizeof((array).at[0]), (n), &(array).cap)
+
+/**
+ * Push value at the end of the array, resize it if necessary.
+ * Mempool usage: pass kr_memreserve and a knot_mm_t* .
+ * @note May fail if the capacity is not reserved.
+ * @return element index on success, <0 on failure
+ */
+#define array_push_mm(array, val, reserve, baton) \
+ (int)((array).len < (array).cap ? ((array).at[(array).len] = val, (array).len++) \
+ : (array_reserve_mm(array, ((array).cap + 1), reserve, baton) < 0 ? -1 \
+ : ((array).at[(array).len] = val, (array).len++)))
+
+/**
+ * Push value at the end of the array, resize it if necessary (plain malloc/free).
+ * @note May fail if the capacity is not reserved.
+ * @return element index on success, <0 on failure
+ */
+#define array_push(array, val) \
+ array_push_mm(array, val, array_std_reserve, NULL)
+
+/**
+ * Pop value from the end of the array.
+ */
+#define array_pop(array) \
+ (array).len -= 1
+
+/**
+ * Remove value at given index.
+ * @return 0 on success, <0 on failure
+ */
+#define array_del(array, i) \
+ (int)((i) < (array).len ? ((array).len -= 1,(array).at[i] = (array).at[(array).len], 0) : -1)
+
+/**
+ * Return last element of the array.
+ * @warning Undefined if the array is empty.
+ */
+#define array_tail(array) \
+ (array).at[(array).len - 1]
+
+/** @} */
diff --git a/lib/generic/lru.c b/lib/generic/lru.c
new file mode 100644
index 0000000..dd2331d
--- /dev/null
+++ b/lib/generic/lru.c
@@ -0,0 +1,250 @@
+/* Copyright (C) 2016-2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "lib/generic/lru.h"
+#include "contrib/murmurhash3/murmurhash3.h"
+#include "contrib/ucw/mempool.h"
+
+typedef struct lru_group lru_group_t;
+
+struct lru_item {
+ uint16_t key_len, val_len; /**< Two bytes should be enough for our purposes. */
+ char data[];
+ /**< Place for both key and value.
+ *
+ * We use "char" to satisfy the C99+ aliasing rules.
+ * See C99 section 6.5 Expressions, paragraph 7.
+ * Any type can be accessed through char-pointer,
+ * so we can use a common struct definition
+ * for all types being held.
+ *
+ * The value address is restricted by val_alignment.
+ * Approach: require slightly larger sizes from the allocator
+ * and shift value on the closest address with val_alignment.
+ */
+};
+
+/** @brief Round the value up to a multiple of mul (a power of two). */
+static inline size_t round_power(size_t size, size_t mult)
+{
+ assert(__builtin_popcount(mult) == 1);
+ size_t res = ((size - 1) & ~(mult - 1)) + mult;
+ assert(__builtin_ctz(res) >= __builtin_ctz(mult));
+ assert(size <= res && res < size + mult);
+ return res;
+}
+
+/** @internal Compute the allocation size for an lru_item. */
+static uint item_size(const struct lru *lru, uint key_len, uint val_len)
+{
+ uint key_end = offsetof(struct lru_item, data) + key_len;
+ return key_end + (lru->val_alignment - 1) + val_len;
+ /* ^^^ worst-case padding length
+ * Well, we might compute the bound a bit more precisely,
+ * as we know that lru_item will get alignment at least
+ * some sizeof(void*) and we know all the lengths,
+ * but let's not complicate it, as the gain would be small anyway. */
+}
+
+/** @internal Return pointer to value in an lru_item. */
+static void * item_val(const struct lru *lru, struct lru_item *it)
+{
+ size_t key_end = it->data + it->key_len - (char *)NULL;
+ size_t val_begin = round_power(key_end, lru->val_alignment);
+ return (char *)NULL + val_begin;
+}
+
+/** @internal Free each item. */
+KR_EXPORT void lru_free_items_impl(struct lru *lru)
+{
+ assert(lru);
+ for (size_t i = 0; i < (1 << (size_t)lru->log_groups); ++i) {
+ lru_group_t *g = &lru->groups[i];
+ for (int j = 0; j < LRU_ASSOC; ++j)
+ mm_free(lru->mm, g->items[j]);
+ }
+}
+
+/** @internal See lru_apply. */
+KR_EXPORT void lru_apply_impl(struct lru *lru, lru_apply_fun f, void *baton)
+{
+ bool ok = lru && f;
+ if (!ok) {
+ assert(false);
+ return;
+ }
+ for (size_t i = 0; i < (1 << (size_t)lru->log_groups); ++i) {
+ lru_group_t *g = &lru->groups[i];
+ for (uint j = 0; j < LRU_ASSOC; ++j) {
+ struct lru_item *it = g->items[j];
+ if (!it)
+ continue;
+ enum lru_apply_do ret =
+ f(it->data, it->key_len, item_val(lru, it), baton);
+ switch(ret) {
+ case LRU_APPLY_DO_EVICT: // evict
+ mm_free(lru->mm, it);
+ g->items[j] = NULL;
+ g->counts[j] = 0;
+ g->hashes[j] = 0;
+ break;
+ default:
+ assert(ret == LRU_APPLY_DO_NOTHING);
+ }
+ }
+ }
+}
+
+/** @internal See lru_create. */
+KR_EXPORT struct lru * lru_create_impl(uint max_slots, uint val_alignment,
+ knot_mm_t *mm_array, knot_mm_t *mm)
+{
+ assert(max_slots && __builtin_popcount(val_alignment) == 1);
+ if (!max_slots)
+ return NULL;
+ // let lru->log_groups = ceil(log2(max_slots / (float) assoc))
+ // without trying for efficiency
+ uint group_count = (max_slots - 1) / LRU_ASSOC + 1;
+ uint log_groups = 0;
+ for (uint s = group_count - 1; s; s /= 2)
+ ++log_groups;
+ group_count = 1 << log_groups;
+ assert(max_slots <= group_count * LRU_ASSOC && group_count * LRU_ASSOC < 2 * max_slots);
+
+ /* Get a sufficiently aligning mm_array if NULL is passed. */
+ if (!mm_array) {
+ static knot_mm_t mm_array_default = { 0 };
+ if (!mm_array_default.ctx)
+ mm_ctx_init_aligned(&mm_array_default, alignof(struct lru));
+ mm_array = &mm_array_default;
+ }
+ assert(mm_array->alloc && mm_array->alloc != (knot_mm_alloc_t)mp_alloc);
+
+ size_t size = offsetof(struct lru, groups[group_count]);
+ struct lru *lru = mm_alloc(mm_array, size);
+ if (unlikely(lru == NULL))
+ return NULL;
+ *lru = (struct lru){
+ .mm = mm,
+ .mm_array = mm_array,
+ .log_groups = log_groups,
+ .val_alignment = val_alignment,
+ };
+ // zeros are a good init
+ memset(lru->groups, 0, size - offsetof(struct lru, groups));
+ return lru;
+}
+
+/** @internal Decrement all counters within a group. */
+static void group_dec_counts(lru_group_t *g) {
+ g->counts[LRU_TRACKED] = LRU_TRACKED;
+ for (uint i = 0; i < LRU_TRACKED + 1; ++i)
+ if (likely(g->counts[i]))
+ --g->counts[i];
+}
+
+/** @internal Increment a counter within a group. */
+static void group_inc_count(lru_group_t *g, int i) {
+ if (likely(++(g->counts[i])))
+ return;
+ g->counts[i] = -1;
+ // We could've decreased or halved all of them, but let's keep the max.
+}
+
+/** @internal Implementation of both getting and insertion.
+ * Note: val_len is only meaningful if do_insert.
+ * *is_new is only meaningful when return value isn't NULL, contains
+ * true when returned lru entry has been allocated right now
+ * if return value is NULL, *is_new remains untouched.
+ */
+KR_EXPORT void * lru_get_impl(struct lru *lru, const char *key, uint key_len,
+ uint val_len, bool do_insert, bool *is_new)
+{
+ bool ok = lru && (key || !key_len) && key_len <= UINT16_MAX
+ && (!do_insert || val_len <= UINT16_MAX);
+ if (!ok) {
+ assert(false);
+ return NULL; // reasonable fallback when not debugging
+ }
+ bool is_new_entry = false;
+ // find the right group
+ uint32_t khash = hash(key, key_len);
+ uint16_t khash_top = khash >> 16;
+ lru_group_t *g = &lru->groups[khash & ((1 << lru->log_groups) - 1)];
+ struct lru_item *it = NULL;
+ uint i;
+ // scan the *stored* elements in the group
+ for (i = 0; i < LRU_ASSOC; ++i) {
+ if (g->hashes[i] == khash_top) {
+ it = g->items[i];
+ if (likely(it && it->key_len == key_len
+ && (key_len == 0 || memcmp(it->data, key, key_len) == 0))) {
+ /* Found a key, but trying to insert a value larger than available
+ * space in the allocated slot, so the entry must be resized to fit. */
+ if (unlikely(do_insert && val_len > it->val_len)) {
+ goto insert;
+ } else {
+ goto found; // to reduce huge nesting depth
+ }
+ }
+ }
+ }
+ // key not found; first try an empty/counted-out place to insert
+ if (do_insert)
+ for (i = 0; i < LRU_ASSOC; ++i)
+ if (g->items[i] == NULL || g->counts[i] == 0)
+ goto insert;
+ // check if we track key's count at least
+ for (i = LRU_ASSOC; i < LRU_TRACKED; ++i) {
+ if (g->hashes[i] == khash_top) {
+ group_inc_count(g, i);
+ if (!do_insert)
+ return NULL;
+ // check if we trumped some stored key
+ for (uint j = 0; j < LRU_ASSOC; ++j)
+ if (unlikely(g->counts[i] > g->counts[j])) {
+ // evict key j, i.e. swap with i
+ --g->counts[i]; // we increment it below
+ SWAP(g->counts[i], g->counts[j]);
+ SWAP(g->hashes[i], g->hashes[j]);
+ i = j;
+ goto insert;
+ }
+ return NULL;
+ }
+ }
+ // not found at all: decrement all counts but only on every LRU_TRACKED occasion
+ if (g->counts[LRU_TRACKED])
+ --g->counts[LRU_TRACKED];
+ else
+ group_dec_counts(g);
+ return NULL;
+insert: // insert into position i (incl. key)
+ assert(i < LRU_ASSOC);
+ g->hashes[i] = khash_top;
+ it = g->items[i];
+ uint new_size = item_size(lru, key_len, val_len);
+ if (it == NULL || new_size != item_size(lru, it->key_len, it->val_len)) {
+ // (re)allocate
+ mm_free(lru->mm, it);
+ it = g->items[i] = mm_alloc(lru->mm, new_size);
+ if (it == NULL)
+ return NULL;
+ }
+ it->key_len = key_len;
+ it->val_len = val_len;
+ if (key_len > 0) {
+ memcpy(it->data, key, key_len);
+ }
+ memset(item_val(lru, it), 0, val_len); // clear the value
+ is_new_entry = true;
+found: // key and hash OK on g->items[i]; now update stamps
+ assert(i < LRU_ASSOC);
+ group_inc_count(g, i);
+ if (is_new) {
+ *is_new = is_new_entry;
+ }
+ return item_val(lru, g->items[i]);
+}
+
diff --git a/lib/generic/lru.h b/lib/generic/lru.h
new file mode 100644
index 0000000..a802b5b
--- /dev/null
+++ b/lib/generic/lru.h
@@ -0,0 +1,241 @@
+/* Copyright (C) 2016-2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+/**
+ * @file lru.h
+ * @brief A lossy cache.
+ *
+ * @note The implementation tries to keep frequent keys and avoid others,
+ * even if "used recently", so it may refuse to store it on lru_get_new().
+ * It uses hashing to split the problem pseudo-randomly into smaller groups,
+ * and within each it tries to approximate relative usage counts of several
+ * most frequent keys/hashes. This tracking is done for *more* keys than
+ * those that are actually stored.
+ *
+ * Example usage:
+ * @code{.c}
+ * // Define new LRU type
+ * typedef lru_t(int) lru_int_t;
+ *
+ * // Create LRU
+ * lru_int_t *lru;
+ * lru_create(&lru, 5, NULL, NULL);
+ *
+ * // Insert some values
+ * int *pi = lru_get_new(lru, "luke", strlen("luke"), NULL);
+ * if (pi)
+ * *pi = 42;
+ * pi = lru_get_new(lru, "leia", strlen("leia"), NULL);
+ * if (pi)
+ * *pi = 24;
+ *
+ * // Retrieve values
+ * int *ret = lru_get_try(lru, "luke", strlen("luke"), NULL);
+ * if (!ret) printf("luke dropped out!\n");
+ * else printf("luke's number is %d\n", *ret);
+ *
+ * char *enemies[] = {"goro", "raiden", "subzero", "scorpion"};
+ * for (int i = 0; i < 4; ++i) {
+ * int *val = lru_get_new(lru, enemies[i], strlen(enemies[i]), NULL);
+ * if (val)
+ * *val = i;
+ * }
+ *
+ * // We're done
+ * lru_free(lru);
+ * @endcode
+ *
+ * \addtogroup generics
+ * @{
+ */
+
+#pragma once
+
+#include <assert.h>
+#include <stdalign.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "contrib/ucw/lib.h"
+#include "lib/utils.h"
+#include "libknot/mm_ctx.h"
+
+/* ================================ Interface ================================ */
+
+/** @brief The type for LRU, parametrized by value type. */
+#define lru_t(type) \
+ union { \
+ type *pdata_t; /* only the *type* information is used */ \
+ struct lru lru; \
+ }
+
+/**
+ * @brief Allocate and initialize an LRU with default associativity.
+ *
+ * The real limit on the number of slots can be a bit larger but less than double.
+ *
+ * @param ptable pointer to a pointer to the LRU
+ * @param max_slots number of slots
+ * @param mm_ctx_array memory context to use for the huge array, NULL for default
+ * If you pass your own, it needs to produce CACHE_ALIGNED allocations (ubsan).
+ * @param mm_ctx memory context to use for individual key-value pairs, NULL for default
+ *
+ * @note The pointers to memory contexts need to remain valid
+ * during the whole life of the structure (or be NULL).
+ */
+/* Pragmas: C11 only standardizes alignof on type names, not on expressions.
+ * That's a GNU extension; in clang it's supported but may generate warnings.
+ * It seems hard to disable warnings that are only supported by some compilers. */
+#define lru_create(ptable, max_slots, mm_ctx_array, mm_ctx) do { \
+ (void)(((__typeof__((*(ptable))->pdata_t))0) == (void *)0); /* typecheck lru_t */ \
+ _Pragma("GCC diagnostic push") \
+ _Pragma("GCC diagnostic ignored \"-Wpragmas\"") \
+ _Pragma("GCC diagnostic ignored \"-Wunknown-pragmas\"") \
+ _Pragma("GCC diagnostic ignored \"-Wgnu-alignof-expression\"") \
+ *(ptable) = (__typeof__(*(ptable))) \
+ lru_create_impl((max_slots), alignof(*( (*(ptable))->pdata_t )), \
+ (mm_ctx_array), (mm_ctx)); \
+ _Pragma("GCC diagnostic pop") \
+ } while (false)
+
+/** @brief Free an LRU created by lru_create (it can be NULL). */
+#define lru_free(table) \
+ lru_free_impl(&(table)->lru)
+
+/** @brief Reset an LRU to the empty state (but preserve any settings). */
+#define lru_reset(table) \
+ lru_reset_impl(&(table)->lru)
+
+/**
+ * @brief Find key in the LRU and return pointer to the corresponding value.
+ *
+ * @param table pointer to LRU
+ * @param key_ lookup key
+ * @param len_ key length
+ * @return pointer to data or NULL if not found
+ */
+#define lru_get_try(table, key_, len_) \
+ (__typeof__((table)->pdata_t)) \
+ lru_get_impl(&(table)->lru, (key_), (len_), -1, false, NULL)
+
+/**
+ * @brief Return pointer to value, inserting if needed (zeroed).
+ *
+ * @param table pointer to LRU
+ * @param key_ lookup key
+ * @param len_ key lengthkeys
+ * @param is_new pointer to bool to store result of operation
+ * (true if entry is newly added, false otherwise; can be NULL).
+ * @return pointer to data or NULL (can be even if memory could be allocated!)
+ */
+#define lru_get_new(table, key_, len_, is_new) \
+ (__typeof__((table)->pdata_t)) \
+ lru_get_impl(&(table)->lru, (key_), (len_), \
+ sizeof(*(table)->pdata_t), true, is_new)
+
+/**
+ * @brief Apply a function to every item in LRU.
+ *
+ * @param table pointer to LRU
+ * @param function enum lru_apply_do (*function)(const char *key, uint len, val_type *val, void *baton)
+ * See enum lru_apply_do for the return type meanings.
+ * @param baton extra pointer passed to each function invocation
+ */
+#define lru_apply(table, function, baton) do { \
+ lru_apply_fun_g(fun_dummy, __typeof__(*(table)->pdata_t)) = 0; \
+ (void)(fun_dummy == (function)); /* produce a warning with incompatible function type */ \
+ lru_apply_impl(&(table)->lru, (lru_apply_fun)(function), (baton)); \
+ } while (false)
+
+/** @brief Possible actions to do with an element. */
+enum lru_apply_do {
+ LRU_APPLY_DO_NOTHING,
+ LRU_APPLY_DO_EVICT,
+ /* maybe more in future*/
+};
+
+/**
+ * @brief Return the real capacity - maximum number of keys holdable within.
+ *
+ * @param table pointer to LRU
+ */
+#define lru_capacity(table) lru_capacity_impl(&(table)->lru)
+
+
+
+/* ======================== Inlined part of implementation ======================== */
+/** @cond internal */
+
+#define lru_apply_fun_g(name, val_type) \
+ enum lru_apply_do (*(name))(const char *key, uint len, val_type *val, void *baton)
+typedef lru_apply_fun_g(lru_apply_fun, void);
+
+#if __GNUC__ >= 4
+ #define CACHE_ALIGNED __attribute__((aligned(64)))
+#else
+ #define CACHE_ALIGNED
+#endif
+
+struct lru;
+void lru_free_items_impl(struct lru *lru);
+struct lru * lru_create_impl(uint max_slots, uint val_alignment,
+ knot_mm_t *mm_array, knot_mm_t *mm);
+void * lru_get_impl(struct lru *lru, const char *key, uint key_len,
+ uint val_len, bool do_insert, bool *is_new);
+void lru_apply_impl(struct lru *lru, lru_apply_fun f, void *baton);
+
+struct lru_item;
+
+#if SIZE_MAX > (1 << 32)
+ /** @internal The number of keys stored within each group. */
+ #define LRU_ASSOC 3
+#else
+ #define LRU_ASSOC 4
+#endif
+/** @internal The number of hashes tracked within each group: 10-1 or 12-1. */
+#define LRU_TRACKED ((64 - sizeof(size_t) * LRU_ASSOC) / 4 - 1)
+
+struct lru_group {
+ uint16_t counts[LRU_TRACKED+1]; /*!< Occurrence counters; the last one is special. */
+ uint16_t hashes[LRU_TRACKED+1]; /*!< Top halves of hashes; the last one is unused. */
+ struct lru_item *items[LRU_ASSOC]; /*!< The full items. */
+} CACHE_ALIGNED;
+
+/* The sizes are chosen so lru_group just fits into a single x86 cache line. */
+static_assert(64 == sizeof(struct lru_group)
+ && 64 == LRU_ASSOC * sizeof(void*) + (LRU_TRACKED+1) * 4,
+ "bad sizing for your sizeof(void*)");
+
+struct lru {
+ struct knot_mm *mm, /**< Memory context to use for keys. */
+ *mm_array; /**< Memory context to use for this structure itself. */
+ uint log_groups; /**< Logarithm of the number of LRU groups. */
+ uint val_alignment; /**< Alignment for the values. */
+ struct lru_group groups[] CACHE_ALIGNED; /**< The groups of items. */
+};
+
+/** @internal See lru_free. */
+static inline void lru_free_impl(struct lru *lru)
+{
+ if (!lru)
+ return;
+ lru_free_items_impl(lru);
+ mm_free(lru->mm_array, lru);
+}
+
+/** @internal See lru_reset. */
+static inline void lru_reset_impl(struct lru *lru)
+{
+ lru_free_items_impl(lru);
+ memset(lru->groups, 0, sizeof(lru->groups[0]) * (1 << lru->log_groups));
+}
+
+/** @internal See lru_capacity. */
+static inline uint lru_capacity_impl(struct lru *lru)
+{
+ assert(lru);
+ return (1 << lru->log_groups) * LRU_ASSOC;
+}
+
+/** @endcond */
+/** @} (addtogroup generics) */
diff --git a/lib/generic/map.c b/lib/generic/map.c
new file mode 100644
index 0000000..9fc3e34
--- /dev/null
+++ b/lib/generic/map.c
@@ -0,0 +1,355 @@
+/*
+ * critbit89 - A crit-bit tree implementation for strings in C89
+ * Written by Jonas Gehring <jonas@jgehring.net>
+ * Implemented key-value storing by Marek Vavrusa <marek.vavrusa@nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * The code makes the assumption that malloc returns pointers aligned at at
+ * least a two-byte boundary. Since the C standard requires that malloc return
+ * pointers that can store any type, there are no commonly-used toolchains for
+ * which this assumption is false.
+ *
+ * See https://github.com/agl/critbit/blob/master/critbit.pdf for reference.
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "map.h"
+#include "lib/utils.h"
+
+ /* Exports */
+#if defined _WIN32 || defined __CYGWIN__
+ #define EXPORT __attribute__ ((dllexport))
+#else
+ #define EXPORT __attribute__ ((visibility ("default")))
+#endif
+
+#ifdef _MSC_VER /* MSVC */
+ typedef unsigned __int8 uint8_t;
+ typedef unsigned __int32 uint32_t;
+ #ifdef _WIN64
+ typedef signed __int64 intptr_t;
+ #else
+ typedef _W64 signed int intptr_t;
+ #endif
+#else /* Not MSVC */
+ #include <stdint.h>
+#endif
+
+typedef struct {
+ void* value;
+ uint8_t key[];
+} cb_data_t;
+
+typedef struct {
+ void *child[2];
+ uint32_t byte;
+ uint8_t otherbits;
+} cb_node_t;
+
+/* Return true if ptr is internal node. */
+static inline int ref_is_internal(const uint8_t *p)
+{
+ return 1 & (intptr_t)p;
+}
+
+/* Get internal node. */
+static inline cb_node_t *ref_get_internal(uint8_t *p)
+{
+ return (cb_node_t *)(p - 1);
+}
+
+/* Static helper functions */
+static void cbt_traverse_delete(map_t *map, void *top)
+{
+ uint8_t *p = top;
+ if (ref_is_internal(p)) {
+ cb_node_t *q = ref_get_internal(p);
+ cbt_traverse_delete(map, q->child[0]);
+ cbt_traverse_delete(map, q->child[1]);
+ mm_free(map->pool, q);
+ } else {
+ mm_free(map->pool, p);
+ }
+}
+
+static int cbt_traverse_prefixed(void *top,
+ int (*callback)(const char *, void *, void *), void *baton)
+{
+ uint8_t *p = top;
+ cb_data_t *x = (cb_data_t *)top;
+
+ if (ref_is_internal(p)) {
+ cb_node_t *q = ref_get_internal(p);
+ int ret = 0;
+
+ ret = cbt_traverse_prefixed(q->child[0], callback, baton);
+ if (ret != 0) {
+ return ret;
+ }
+ ret = cbt_traverse_prefixed(q->child[1], callback, baton);
+ if (ret != 0) {
+ return ret;
+ }
+ return 0;
+ }
+
+ return (callback)((const char *)x->key, x->value, baton);
+}
+
+static cb_data_t *cbt_make_data(map_t *map, const uint8_t *str, size_t len, void *value)
+{
+ cb_data_t *x = mm_alloc(map->pool, sizeof(cb_data_t) + len);
+ if (x != NULL) {
+ x->value = value;
+ memcpy(x->key, str, len);
+ }
+ return x;
+}
+
+/*! Like map_contains, but also set the value, if passed and found. */
+static int cbt_get(map_t *map, const char *str, void **value)
+{
+ const uint8_t *ubytes = (void *)str;
+ const size_t ulen = strlen(str);
+ uint8_t *p = map->root;
+ cb_data_t *x = NULL;
+
+ if (p == NULL) {
+ return 0;
+ }
+
+ while (ref_is_internal(p)) {
+ cb_node_t *q = ref_get_internal(p);
+ uint8_t c = 0;
+ int direction;
+
+ if (q->byte < ulen) {
+ c = ubytes[q->byte];
+ }
+ direction = (1 + (q->otherbits | c)) >> 8;
+
+ p = q->child[direction];
+ }
+
+ x = (cb_data_t *)p;
+ if (strcmp(str, (const char *)x->key) == 0) {
+ if (value != NULL) {
+ *value = x->value;
+ }
+ return 1;
+ }
+
+ return 0;
+}
+
+/*! Returns non-zero if map contains str */
+EXPORT int map_contains(map_t *map, const char *str)
+{
+ return cbt_get(map, str, NULL);
+}
+
+EXPORT void *map_get(map_t *map, const char *str)
+{
+ void *v = NULL;
+ cbt_get(map, str, &v);
+ return v;
+}
+
+EXPORT int map_set(map_t *map, const char *str, void *val)
+{
+ const uint8_t *const ubytes = (void *)str;
+ const size_t ulen = strlen(str);
+ uint8_t *p = map->root;
+ uint8_t c = 0, *x = NULL;
+ uint32_t newbyte = 0;
+ uint32_t newotherbits = 0;
+ int direction = 0, newdirection = 0;
+ cb_node_t *newnode = NULL;
+ cb_data_t *data = NULL;
+ void **wherep = NULL;
+
+ if (p == NULL) {
+ map->root = cbt_make_data(map, (const uint8_t *)str, ulen + 1, val);
+ if (map->root == NULL) {
+ return ENOMEM;
+ }
+ return 0;
+ }
+
+ while (ref_is_internal(p)) {
+ cb_node_t *q = ref_get_internal(p);
+ c = 0;
+ if (q->byte < ulen) {
+ c = ubytes[q->byte];
+ }
+ direction = (1 + (q->otherbits | c)) >> 8;
+
+ p = q->child[direction];
+ }
+
+ data = (cb_data_t *)p;
+ for (newbyte = 0; newbyte < ulen; ++newbyte) {
+ if (data->key[newbyte] != ubytes[newbyte]) {
+ newotherbits = data->key[newbyte] ^ ubytes[newbyte];
+ goto different_byte_found;
+ }
+ }
+
+ if (data->key[newbyte] != 0) {
+ newotherbits = data->key[newbyte];
+ goto different_byte_found;
+ }
+ data->value = val;
+ return 1;
+
+different_byte_found:
+ newotherbits |= newotherbits >> 1;
+ newotherbits |= newotherbits >> 2;
+ newotherbits |= newotherbits >> 4;
+ newotherbits = (newotherbits & ~(newotherbits >> 1)) ^ 255;
+ c = data->key[newbyte];
+ newdirection = (1 + (newotherbits | c)) >> 8;
+
+ newnode = mm_alloc(map->pool, sizeof(cb_node_t));
+ if (newnode == NULL) {
+ return ENOMEM;
+ }
+
+ x = (uint8_t *)cbt_make_data(map, ubytes, ulen + 1, val);
+ if (x == NULL) {
+ mm_free(map->pool, newnode);
+ return ENOMEM;
+ }
+
+ newnode->byte = newbyte;
+ newnode->otherbits = newotherbits;
+ newnode->child[1 - newdirection] = x;
+
+ /* Insert into map */
+ wherep = &map->root;
+ for (;;) {
+ cb_node_t *q;
+ p = *wherep;
+ if (!ref_is_internal(p)) {
+ break;
+ }
+
+ q = ref_get_internal(p);
+ if (q->byte > newbyte) {
+ break;
+ }
+ if (q->byte == newbyte && q->otherbits > newotherbits) {
+ break;
+ }
+
+ c = 0;
+ if (q->byte < ulen) {
+ c = ubytes[q->byte];
+ }
+ direction = (1 + (q->otherbits | c)) >> 8;
+ wherep = q->child + direction;
+ }
+
+ newnode->child[newdirection] = *wherep;
+ *wherep = (void *)(1 + (char *)newnode);
+ return 0;
+}
+
+/*! Deletes str from the map, returns 0 on success */
+EXPORT int map_del(map_t *map, const char *str)
+{
+ const uint8_t *ubytes = (void *)str;
+ const size_t ulen = strlen(str);
+ uint8_t *p = map->root;
+ void **wherep = NULL, **whereq = NULL;
+ cb_node_t *q = NULL;
+ cb_data_t *data = NULL;
+ int direction = 0;
+
+ if (map->root == NULL) {
+ return 1;
+ }
+ wherep = &map->root;
+
+ while (ref_is_internal(p)) {
+ uint8_t c = 0;
+ whereq = wherep;
+ q = ref_get_internal(p);
+
+ if (q->byte < ulen) {
+ c = ubytes[q->byte];
+ }
+ direction = (1 + (q->otherbits | c)) >> 8;
+ wherep = q->child + direction;
+ p = *wherep;
+ }
+
+ data = (cb_data_t *)p;
+ if (strcmp(str, (const char *)data->key) != 0) {
+ return 1;
+ }
+ mm_free(map->pool, p);
+
+ if (!whereq) {
+ map->root = NULL;
+ return 0;
+ }
+
+ *whereq = q->child[1 - direction];
+ mm_free(map->pool, q);
+ return 0;
+}
+
+/*! Clears the given map */
+EXPORT void map_clear(map_t *map)
+{
+ if (map->root) {
+ cbt_traverse_delete(map, map->root);
+ }
+ map->root = NULL;
+}
+
+/*! Calls callback for all strings in map with the given prefix */
+EXPORT int map_walk_prefixed(map_t *map, const char *prefix,
+ int (*callback)(const char *, void *, void *), void *baton)
+{
+ if (!map) {
+ return 0;
+ }
+
+ const uint8_t *ubytes = (void *)prefix;
+ const size_t ulen = strlen(prefix);
+ uint8_t *p = map->root;
+ uint8_t *top = p;
+ cb_data_t *data = NULL;
+
+ if (p == NULL) {
+ return 0;
+ }
+
+ while (ref_is_internal(p)) {
+ cb_node_t *q = ref_get_internal(p);
+ uint8_t c = 0;
+ int direction;
+
+ if (q->byte < ulen) {
+ c = ubytes[q->byte];
+ }
+ direction = (1 + (q->otherbits | c)) >> 8;
+
+ p = q->child[direction];
+ if (q->byte < ulen) {
+ top = p;
+ }
+ }
+
+ data = (cb_data_t *)p;
+ if (strlen((const char *)data->key) < ulen || memcmp(data->key, prefix, ulen) != 0) {
+ return 0; /* No strings match */
+ }
+
+ return cbt_traverse_prefixed(top, callback, baton);
+}
diff --git a/lib/generic/map.h b/lib/generic/map.h
new file mode 100644
index 0000000..cec9d39
--- /dev/null
+++ b/lib/generic/map.h
@@ -0,0 +1,116 @@
+/*
+ * critbit89 - A crit-bit map implementation for strings in C89
+ * Written by Jonas Gehring <jonas@jgehring.net>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/**
+ * @file map.h
+ * @brief A Crit-bit tree key-value map implementation.
+ *
+ * @warning If the user provides a custom allocator, it must return addresses aligned to 2B boundary.
+ *
+ * # Example usage:
+ *
+ * @code{.c}
+ * map_t map = map_make(NULL);
+ *
+ * // Custom allocator (optional)
+ * map.malloc = &mymalloc;
+ * map.baton = &mymalloc_context;
+ *
+ * // Insert k-v pairs
+ * int values = { 42, 53, 64 };
+ * if (map_set(&map, "princess", &values[0]) != 0 ||
+ * map_set(&map, "prince", &values[1]) != 0 ||
+ * map_set(&map, "leia", &values[2]) != 0) {
+ * fail();
+ * }
+ *
+ * // Test membership
+ * if (map_contains(&map, "leia")) {
+ * success();
+ * }
+ *
+ * // Prefix search
+ * int i = 0;
+ * int count(const char *k, void *v, void *ext) { (*(int *)ext)++; return 0; }
+ * if (map_walk_prefixed(map, "princ", count, &i) == 0) {
+ * printf("%d matches\n", i);
+ * }
+ *
+ * // Delete
+ * if (map_del(&map, "badkey") != 0) {
+ * fail(); // No such key
+ * }
+ *
+ * // Clear the map
+ * map_clear(&map);
+ * @endcode
+ *
+ * \addtogroup generics
+ * @{
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct knot_mm; /* avoid the unnecessary include */
+
+/** Main data structure */
+typedef struct {
+ void *root;
+ struct knot_mm *pool;
+} map_t;
+
+/** Creates an new empty critbit map. Pass NULL for malloc+free. */
+static inline map_t map_make(struct knot_mm *pool)
+{
+ return (map_t){ .root = NULL, .pool = pool };
+}
+
+/** Returns non-zero if map contains str */
+int map_contains(map_t *map, const char *str);
+
+/** Returns value if map contains str. Note: NULL may mean two different things. */
+void *map_get(map_t *map, const char *str);
+
+/** Inserts str into map. Returns 0 if new, 1 if replaced, or ENOMEM. */
+int map_set(map_t *map, const char *str, void *val);
+
+/** Deletes str from the map, returns 0 on suceess */
+int map_del(map_t *map, const char *str);
+
+/** Clears the given map */
+void map_clear(map_t *map);
+
+/**
+ * Calls callback for all strings in map
+ * See @fn map_walk_prefixed() for documentation on parameters.
+ */
+#define map_walk(map, callback, baton) \
+ map_walk_prefixed((map), "", (callback), (baton))
+
+/**
+ * Calls callback for all strings in map with the given prefix.
+ * Returns value immediately if a callback returns nonzero.
+ *
+ * @param map
+ * @param prefix required string prefix (empty => all strings)
+ * @param callback callback parameters are (key, value, baton)
+ * @param baton passed uservalue
+ */
+int map_walk_prefixed(map_t *map, const char *prefix,
+ int (*callback)(const char *, void *, void *), void *baton);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+/** @} */
diff --git a/lib/generic/map.spdx b/lib/generic/map.spdx
new file mode 100644
index 0000000..cc39886
--- /dev/null
+++ b/lib/generic/map.spdx
@@ -0,0 +1,10 @@
+SPDXVersion: SPDX-2.1
+DataLicense: CC0-1.0
+SPDXID: SPDXRef-DOCUMENT
+DocumentName: map
+DocumentNamespace: http://spdx.org/spdxdocs/spdx-v2.1-d9b4db4c-062f-4add-89b6-f603224f5a2c
+
+PackageName: critbit89
+PackageDownloadLocation: git+https://github.com/jgehring/critbit89.git@4f7e1d2a5f4794e0d08cb408346973fb1e39489c#critbit.c
+PackageOriginator: Person: Jonas Gehring (jonas@jgehring.net)
+PackageLicenseDeclared: CC0-1.0
diff --git a/lib/generic/pack.h b/lib/generic/pack.h
new file mode 100644
index 0000000..463bb51
--- /dev/null
+++ b/lib/generic/pack.h
@@ -0,0 +1,237 @@
+/* Copyright (C) 2015-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/**
+ * @file pack.h
+ * @brief A length-prefixed list of objects, also an array list.
+ *
+ * Each object is prefixed by item length, unlike array this structure
+ * permits variable-length data. It is also equivallent to forward-only list
+ * backed by an array.
+ *
+ * @note Maximum object size is 2^16 bytes, see ::pack_objlen_t
+ * @todo If some mistake happens somewhere, the access may end up in an infinite loop.
+ * (equality comparison on pointers)
+ *
+ * # Example usage:
+ *
+ * @code{.c}
+ * pack_t pack;
+ * pack_init(pack);
+ *
+ * // Reserve 2 objects, 6 bytes total
+ * pack_reserve(pack, 2, 4 + 2);
+ *
+ * // Push 2 objects
+ * pack_obj_push(pack, U8("jedi"), 4)
+ * pack_obj_push(pack, U8("\xbe\xef"), 2);
+ *
+ * // Iterate length-value pairs
+ * uint8_t *it = pack_head(pack);
+ * while (it != pack_tail(pack)) {
+ * uint8_t *val = pack_obj_val(it);
+ * it = pack_obj_next(it);
+ * }
+ *
+ * // Remove object
+ * pack_obj_del(pack, U8("jedi"), 4);
+ *
+ * pack_clear(pack);
+ * @endcode
+ *
+ * \addtogroup generics
+ * @{
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <string.h>
+#include "array.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Packed object length type. */
+typedef uint16_t pack_objlen_t;
+
+/** Pack is defined as an array of bytes */
+typedef array_t(uint8_t) pack_t;
+
+/** Zero-initialize the pack. */
+#define pack_init(pack) \
+ array_init(pack)
+
+/** Make the pack empty and free pointed-to memory (plain malloc/free). */
+#define pack_clear(pack) \
+ array_clear(pack)
+
+/** Make the pack empty and free pointed-to memory.
+ * Mempool usage: pass mm_free and a knot_mm_t* . */
+#define pack_clear_mm(pack, free, baton) \
+ array_clear_mm((pack), (free), (baton))
+
+/** Reserve space for *additional* objects in the pack (plain malloc/free).
+ * @return 0 if success, <0 on failure */
+#define pack_reserve(pack, objs_count, objs_len) \
+ pack_reserve_mm((pack), (objs_count), (objs_len), array_std_reserve, NULL)
+
+/** Reserve space for *additional* objects in the pack.
+ * Mempool usage: pass kr_memreserve and a knot_mm_t* .
+ * @return 0 if success, <0 on failure */
+#define pack_reserve_mm(pack, objs_count, objs_len, reserve, baton) \
+ array_reserve_mm((pack), (pack).len + (sizeof(pack_objlen_t)*(objs_count) + (objs_len)), (reserve), (baton))
+
+/** Return pointer to first packed object.
+ *
+ * Recommended way to iterate:
+ * for (uint8_t *it = pack_head(pack); it != pack_tail(pack); it = pack_obj_next(it))
+ */
+#define pack_head(pack) \
+ ((pack).len > 0 ? &((pack).at[0]) : NULL)
+
+/** Return pack end pointer. */
+#define pack_tail(pack) \
+ ((pack).len > 0 ? &((pack).at[(pack).len]) : NULL)
+
+/** Return packed object length. */
+static inline pack_objlen_t pack_obj_len(uint8_t *it)
+{
+ pack_objlen_t len = 0;
+ if (it != NULL)
+ memcpy(&len, it, sizeof(len));
+ return len;
+}
+
+/** Return packed object value. */
+static inline uint8_t *pack_obj_val(uint8_t *it)
+{
+ if (it == NULL) {
+ assert(it);
+ return NULL;
+ }
+ return it + sizeof(pack_objlen_t);
+}
+
+/** Return pointer to next packed object. */
+static inline uint8_t *pack_obj_next(uint8_t *it)
+{
+ if (it == NULL) {
+ assert(it);
+ return NULL;
+ }
+ return pack_obj_val(it) + pack_obj_len(it);
+}
+
+/** Return pointer to the last packed object. */
+static inline uint8_t *pack_last(pack_t pack)
+{
+ if (pack.len == 0) {
+ return NULL;
+ }
+ uint8_t *it = pack_head(pack);
+ uint8_t *tail = pack_tail(pack);
+ while (true) {
+ uint8_t *next = pack_obj_next(it);
+ if (next == tail) {
+ return it;
+ }
+ it = next;
+ }
+}
+
+/** Push object to the end of the pack
+ * @return 0 on success, negative number on failure
+ */
+static inline int pack_obj_push(pack_t *pack, const uint8_t *obj, pack_objlen_t len)
+{
+ if (pack == NULL || obj == NULL) {
+ assert(false);
+ return kr_error(EINVAL);
+ }
+ size_t packed_len = len + sizeof(len);
+ if (pack->len + packed_len > pack->cap) {
+ return kr_error(ENOSPC);
+ }
+
+ uint8_t *endp = pack->at + pack->len;
+ memcpy(endp, (char *)&len, sizeof(len));
+ memcpy(endp + sizeof(len), obj, len);
+ pack->len += packed_len;
+ return 0;
+}
+
+/** Returns a pointer to packed object.
+ * @return pointer to packed object or NULL
+ */
+static inline uint8_t *pack_obj_find(pack_t *pack, const uint8_t *obj, pack_objlen_t len)
+{
+ if (pack == NULL || obj == NULL) {
+ assert(obj != NULL);
+ return NULL;
+ }
+ uint8_t *endp = pack_tail(*pack);
+ uint8_t *it = pack_head(*pack);
+ while (it != endp) {
+ uint8_t *val = pack_obj_val(it);
+ if (pack_obj_len(it) == len && memcmp(obj, val, len) == 0) {
+ return it;
+ }
+ it = pack_obj_next(it);
+ }
+ return NULL;
+}
+
+/** Delete object from the pack
+ * @return 0 on success, negative number on failure
+ */
+static inline int pack_obj_del(pack_t *pack, const uint8_t *obj, pack_objlen_t len)
+{
+ if (pack == NULL || obj == NULL) {
+ assert(obj != NULL);
+ return kr_error(EINVAL);
+ }
+ uint8_t *endp = pack_tail(*pack);
+ uint8_t *it = pack_obj_find(pack, obj, len);
+ if (it) {
+ size_t packed_len = len + sizeof(len);
+ memmove(it, it + packed_len, endp - it - packed_len);
+ pack->len -= packed_len;
+ return 0;
+ }
+ return -1;
+}
+
+/** Clone a pack, replacing destination pack; (*dst == NULL) is valid input.
+ * @return kr_error(ENOMEM) on allocation failure. */
+static inline int pack_clone(pack_t **dst, const pack_t *src, knot_mm_t *pool)
+{
+ if (!dst || !src) {
+ assert(false);
+ return kr_error(EINVAL);
+ }
+ /* Get a valid pack_t. */
+ if (!*dst) {
+ *dst = mm_alloc(pool, sizeof(pack_t));
+ if (!*dst) return kr_error(ENOMEM);
+ pack_init(**dst);
+ /* Clone data only if needed */
+ if (src->len == 0) return kr_ok();
+ }
+ /* Replace the contents of the pack_t. */
+ int ret = array_reserve_mm(**dst, src->len, kr_memreserve, pool);
+ if (ret < 0) {
+ return kr_error(ENOMEM);
+ }
+ memcpy((*dst)->at, src->at, src->len);
+ (*dst)->len = src->len;
+ return kr_ok();
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+/** @} */
diff --git a/lib/generic/queue.c b/lib/generic/queue.c
new file mode 100644
index 0000000..f46050f
--- /dev/null
+++ b/lib/generic/queue.c
@@ -0,0 +1,112 @@
+/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "lib/generic/queue.h"
+#include <string.h>
+
+void queue_init_impl(struct queue *q, size_t item_size)
+{
+ q->len = 0;
+ q->item_size = item_size;
+ q->head = q->tail = NULL;
+ /* Take 128 B (two x86 cache lines), except a small margin
+ * that the allocator can use for its overhead.
+ * Normally (64-bit pointers) this means 16 B header + 13*8 B data. */
+ q->chunk_cap = (128 - offsetof(struct queue_chunk, data)
+ - sizeof(size_t)
+ ) / item_size;
+ if (!q->chunk_cap) q->chunk_cap = 1; /* item_size big enough by itself */
+}
+
+void queue_deinit_impl(struct queue *q)
+{
+ assert(q);
+ struct queue_chunk *p = q->head;
+ while (p != NULL) {
+ struct queue_chunk *pf = p;
+ p = p->next;
+ free(pf);
+ }
+#ifndef NDEBUG
+ memset(q, 0, sizeof(*q));
+#endif
+}
+
+static struct queue_chunk * queue_chunk_new(const struct queue *q)
+{
+ struct queue_chunk *c = malloc(offsetof(struct queue_chunk, data)
+ + q->chunk_cap * q->item_size);
+ if (unlikely(!c)) abort(); // simplify stuff
+ memset(c, 0, offsetof(struct queue_chunk, data));
+ c->cap = q->chunk_cap;
+ /* ->begin and ->end are zero, i.e. we optimize for _push
+ * and not _push_head, by default. */
+ return c;
+}
+
+/* Return pointer to the space for the new element. */
+void * queue_push_impl(struct queue *q)
+{
+ assert(q);
+ struct queue_chunk *t = q->tail; // shorthand
+ if (unlikely(!t)) {
+ assert(!q->head && !q->len);
+ q->head = q->tail = t = queue_chunk_new(q);
+ } else
+ if (t->end == t->cap) {
+ if (t->begin * 2 >= t->cap) {
+ /* Utilization is below 50%, so let's shift (no overlap). */
+ memcpy(t->data, t->data + t->begin * q->item_size,
+ (t->end - t->begin) * q->item_size);
+ t->end -= t->begin;
+ t->begin = 0;
+ } else {
+ /* Let's grow the tail by another chunk. */
+ assert(!t->next);
+ t->next = queue_chunk_new(q);
+ t = q->tail = t->next;
+ }
+ }
+ assert(t->end < t->cap);
+ ++(q->len);
+ ++(t->end);
+ return t->data + q->item_size * (t->end - 1);
+}
+
+/* Return pointer to the space for the new element. */
+void * queue_push_head_impl(struct queue *q)
+{
+ /* When we have choice, we optimize for further _push_head,
+ * i.e. when shifting or allocating a chunk,
+ * we store items on the tail-end of the chunk. */
+ assert(q);
+ struct queue_chunk *h = q->head; // shorthand
+ if (unlikely(!h)) {
+ assert(!q->tail && !q->len);
+ h = q->head = q->tail = queue_chunk_new(q);
+ h->begin = h->end = h->cap;
+ } else
+ if (h->begin == 0) {
+ if (h->end * 2 <= h->cap) {
+ /* Utilization is below 50%, so let's shift (no overlap).
+ * Computations here are simplified due to h->begin == 0. */
+ const int cnt = h->end;
+ memcpy(h->data + (h->cap - cnt) * q->item_size, h->data,
+ cnt * q->item_size);
+ h->begin = h->cap - cnt;
+ h->end = h->cap;
+ } else {
+ /* Let's grow the head by another chunk. */
+ h = queue_chunk_new(q);
+ h->next = q->head;
+ q->head = h;
+ h->begin = h->end = h->cap;
+ }
+ }
+ assert(h->begin > 0);
+ --(h->begin);
+ ++(q->len);
+ return h->data + q->item_size * h->begin;
+}
+
diff --git a/lib/generic/queue.h b/lib/generic/queue.h
new file mode 100644
index 0000000..418e19c
--- /dev/null
+++ b/lib/generic/queue.h
@@ -0,0 +1,252 @@
+/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+/**
+ * @file queue.h
+ * @brief A queue, usable for FIFO and LIFO simultaneously.
+ *
+ * Both the head and tail of the queue can be accessed and pushed to,
+ * but only the head can be popped from.
+ *
+ * @note The implementation uses a singly linked list of blocks ("chunks")
+ * where each block stores an array of values (for better efficiency).
+ *
+ * Example usage:
+ * @code{.c}
+ // define new queue type, and init a new queue instance
+ typedef queue_t(int) queue_int_t;
+ queue_int_t q;
+ queue_init(q);
+ // do some operations
+ queue_push(q, 1);
+ queue_push(q, 2);
+ queue_push(q, 3);
+ queue_push(q, 4);
+ queue_pop(q);
+ assert(queue_head(q) == 2);
+ assert(queue_tail(q) == 4);
+
+ // you may iterate
+ typedef queue_it_t(int) queue_it_int_t;
+ for (queue_it_int_t it = queue_it_begin(q); !queue_it_finished(it);
+ queue_it_next(it)) {
+ ++queue_it_val(it);
+ }
+ assert(queue_tail(q) == 5);
+
+ queue_push_head(q, 0);
+ ++queue_tail(q);
+ assert(queue_tail(q) == 6);
+ // free it up
+ queue_deinit(q);
+
+ // you may use dynamic allocation for the type itself
+ queue_int_t *qm = malloc(sizeof(queue_int_t));
+ queue_init(*qm);
+ queue_deinit(*qm);
+ free(qm);
+ * @endcode
+ *
+ * \addtogroup generics
+ * @{
+ */
+
+#pragma once
+
+#include "lib/defines.h"
+#include "contrib/ucw/lib.h"
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/** @brief The type for queue, parametrized by value type. */
+#define queue_t(type) \
+ union { \
+ type *pdata_t; /* only the *type* information is used */ \
+ struct queue queue; \
+ }
+
+/** @brief Initialize a queue. You can malloc() it the usual way. */
+#define queue_init(q) do { \
+ (void)(((__typeof__(((q).pdata_t)))0) == (void *)0); /* typecheck queue_t */ \
+ queue_init_impl(&(q).queue, sizeof(*(q).pdata_t)); \
+ } while (false)
+
+/** @brief De-initialize a queue: make it invalid and free any inner allocations. */
+#define queue_deinit(q) \
+ queue_deinit_impl(&(q).queue)
+
+/** @brief Push data to queue's tail. (Type-safe version; use _impl() otherwise.) */
+#define queue_push(q, data) \
+ *((__typeof__((q).pdata_t)) queue_push_impl(&(q).queue)) = data
+
+/** @brief Push data to queue's head. (Type-safe version; use _impl() otherwise.) */
+#define queue_push_head(q, data) \
+ *((__typeof__((q).pdata_t)) queue_push_head_impl(&(q).queue)) = data
+
+/** @brief Remove the element at the head.
+ * The queue must not be empty. */
+#define queue_pop(q) \
+ queue_pop_impl(&(q).queue)
+
+/** @brief Return a "reference" to the element at the head (it's an L-value).
+ * The queue must not be empty. */
+#define queue_head(q) \
+ ( *(__typeof__((q).pdata_t)) queue_head_impl(&(q).queue) )
+
+/** @brief Return a "reference" to the element at the tail (it's an L-value).
+ * The queue must not be empty. */
+#define queue_tail(q) \
+ ( *(__typeof__((q).pdata_t)) queue_tail_impl(&(q).queue) )
+
+/** @brief Return the number of elements in the queue (very efficient). */
+#define queue_len(q) \
+ ((const size_t)(q).queue.len)
+
+
+/** @brief Type for queue iterator, parametrized by value type.
+ * It's a simple structure that owns no other resources.
+ * You may NOT use it after doing any push or pop (without _begin again). */
+#define queue_it_t(type) \
+ union { \
+ type *pdata_t; /* only the *type* information is used */ \
+ struct queue_it iter; \
+ }
+
+/** @brief Initialize a queue iterator at the head of the queue.
+ * If you use this in assignment (instead of initialization),
+ * you will unfortunately need to add corresponding type-cast in front.
+ * Beware: there's no type-check between queue and iterator! */
+#define queue_it_begin(q) \
+ { .iter = queue_it_begin_impl(&(q).queue) }
+
+/** @brief Return a "reference" to the current element (it's an L-value) . */
+#define queue_it_val(it) \
+ ( *(__typeof__((it).pdata_t)) queue_it_val_impl(&(it).iter) )
+
+/** @brief Test if the iterator has gone past the last element.
+ * If it has, you may not use _val or _next. */
+#define queue_it_finished(it) \
+ queue_it_finished_impl(&(it).iter)
+
+/** @brief Advance the iterator to the next element. */
+#define queue_it_next(it) \
+ queue_it_next_impl(&(it).iter)
+
+
+
+/* ====================== Internal for the implementation ================== */
+/** @cond internal */
+
+struct queue;
+/* Non-inline functions are exported to be usable from daemon. */
+KR_EXPORT void queue_init_impl(struct queue *q, size_t item_size);
+KR_EXPORT void queue_deinit_impl(struct queue *q);
+KR_EXPORT void * queue_push_impl(struct queue *q);
+KR_EXPORT void * queue_push_head_impl(struct queue *q);
+
+struct queue_chunk;
+struct queue {
+ size_t len; /**< the current number of items in queue */
+ uint16_t chunk_cap; /**< max. number of items in each chunk */
+ uint16_t item_size; /**< sizeof() each item */
+ struct queue_chunk *head, *tail; /*< first and last chunk (or NULLs) */
+};
+
+struct queue_chunk {
+ struct queue_chunk *next; /*< *head -> ... -> *tail; each is non-empty */
+ int16_t begin, end, cap, pad_; /*< indices: zero is closest to head */
+ /*< We could fit into uint8_t for example, but the choice of (3+1)*2 bytes
+ * is a compromise between wasting space and getting a good alignment.
+ * In particular, queue_t(type*) will store the pointers on addresses
+ * aligned to the pointer size, on both 64-bit and 32-bit platforms.
+ */
+ char data[];
+ /**< The item data. We use "char" to satisfy the C99+ aliasing rules.
+ * See C99 section 6.5 Expressions, paragraph 7.
+ * Any type can be accessed through char-pointer,
+ * so we can use a common struct definition
+ * for all types being held.
+ */
+};
+
+static inline void * queue_head_impl(const struct queue *q)
+{
+ assert(q);
+ struct queue_chunk *h = q->head;
+ assert(h && h->end > h->begin);
+ return h->data + h->begin * q->item_size;
+}
+
+static inline void * queue_tail_impl(const struct queue *q)
+{
+ assert(q);
+ struct queue_chunk *t = q->tail;
+ assert(t && t->end > t->begin);
+ return t->data + (t->end - 1) * q->item_size;
+}
+
+static inline void queue_pop_impl(struct queue *q)
+{
+ assert(q);
+ struct queue_chunk *h = q->head;
+ assert(h && h->end > h->begin);
+ if (h->end - h->begin == 1) {
+ /* removing the last element in the chunk */
+ assert((q->len == 1) == (q->head == q->tail));
+ if (q->len == 1) {
+ q->tail = NULL;
+ assert(!h->next);
+ } else {
+ assert(h->next);
+ }
+ q->head = h->next;
+ free(h);
+ } else {
+ ++(h->begin);
+ }
+ --(q->len);
+}
+
+
+struct queue_it {
+ struct queue_chunk *chunk;
+ int16_t pos, item_size;
+};
+
+static inline struct queue_it queue_it_begin_impl(struct queue *q)
+{
+ assert(q);
+ return (struct queue_it){
+ .chunk = q->head,
+ .pos = q->head ? q->head->begin : -1,
+ .item_size = q->item_size,
+ };
+}
+
+static inline bool queue_it_finished_impl(struct queue_it *it)
+{
+ return it->chunk == NULL || it->pos >= it->chunk->end;
+}
+
+static inline void * queue_it_val_impl(struct queue_it *it)
+{
+ assert(!queue_it_finished_impl(it));
+ return it->chunk->data + it->pos * it->item_size;
+}
+
+static inline void queue_it_next_impl(struct queue_it *it)
+{
+ assert(!queue_it_finished_impl(it));
+ ++(it->pos);
+ if (it->pos < it->chunk->end)
+ return;
+ it->chunk = it->chunk->next;
+ it->pos = it->chunk ? it->chunk->begin : -1;
+}
+
+/** @endcond (internal) */
+/** @} (addtogroup generics) */
+
diff --git a/lib/generic/set.h b/lib/generic/set.h
new file mode 100644
index 0000000..9f6eb80
--- /dev/null
+++ b/lib/generic/set.h
@@ -0,0 +1,93 @@
+/* Copyright (C) 2015-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/**
+ * @file set.h
+ * @brief A set abstraction implemented on top of map.
+ *
+ * @note The API is based on map.h, see it for more examples.
+ *
+ * # Example usage:
+ *
+ * @code{.c}
+ * set_t set = set_make(NULL);
+ *
+ * // Insert keys
+ * if (set_add(&set, "princess") != 0 ||
+ * set_add(&set, "prince") != 0 ||
+ * set_add(&set, "leia") != 0) {
+ * fail();
+ * }
+ *
+ * // Test membership
+ * if (set_contains(&set, "leia")) {
+ * success();
+ * }
+ *
+ * // Prefix search
+ * int i = 0;
+ * int count(const char *s, void *n) { (*(int *)n)++; return 0; }
+ * if (set_walk_prefixed(set, "princ", count, &i) == 0) {
+ * printf("%d matches\n", i);
+ * }
+ *
+ * // Delete
+ * if (set_del(&set, "badkey") != 0) {
+ * fail(); // No such key
+ * }
+ *
+ * // Clear the set
+ * set_clear(&set);
+ * @endcode
+ *
+ * \addtogroup generics
+ * @{
+ */
+
+#pragma once
+
+#include <stddef.h>
+#include "map.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef map_t set_t;
+typedef int (set_walk_cb)(const char *, void *);
+
+/*! Creates an new, empty critbit set */
+#define set_make \
+ map_make
+
+/*! Returns non-zero if set contains str */
+#define set_contains(set, str) \
+ map_contains((set), (str))
+
+/*! Inserts str into set. Returns 0 if new, 1 if already present, or ENOMEM. */
+#define set_add(set, str) \
+ map_set((set), (str), (void *)1)
+
+/*! Deletes str from the set, returns 0 on suceess */
+#define set_del(set, str) \
+ map_del((set), (str))
+
+/*! Clears the given set */
+#define set_clear(set) \
+ map_clear(set)
+
+/*! Calls callback for all strings in map */
+#define set_walk(set, callback, baton) \
+ map_walk_prefixed((set), "", (callback), (baton))
+
+/*! Calls callback for all strings in set with the given prefix */
+#define set_walk_prefixed(set, prefix, callback, baton) \
+ map_walk_prefixed((set), (prefix), (callback), (baton))
+
+
+#ifdef __cplusplus
+}
+#endif
+
+/** @} */
diff --git a/lib/generic/test_array.c b/lib/generic/test_array.c
new file mode 100644
index 0000000..98c5958
--- /dev/null
+++ b/lib/generic/test_array.c
@@ -0,0 +1,99 @@
+/* Copyright (C) 2015-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "tests/unit/test.h"
+#include "lib/generic/array.h"
+
+knot_mm_t global_mm;
+
+static void test_array(void **state)
+{
+ int ret = 0;
+ array_t(int) arr;
+ array_init(arr);
+
+ /* Basic access */
+ assert_int_equal(arr.len, 0);
+ assert_int_equal(array_push(arr, 5), 0);
+ assert_int_equal(arr.at[0], 5);
+ assert_int_equal(array_tail(arr), 5);
+ array_clear(arr);
+
+ /* Reserve capacity and fill. */
+ assert_true(array_reserve(arr, 5) >= 0);
+ for (unsigned i = 0; i < 100; ++i) {
+ ret = array_push(arr, i);
+ assert_true(ret >= 0);
+ }
+
+ /* Make sure reservation holds. */
+ assert_true(array_reserve(arr, 5) >= 0);
+
+ /* Delete elements. */
+ array_del(arr, 0);
+ while (arr.len > 0) {
+ array_pop(arr);
+ }
+
+ /* Overfill. */
+ for (unsigned i = 0; i < 4096; ++i) {
+ ret = array_push(arr, i);
+ assert_true(ret >= 0);
+ }
+
+ array_clear(arr);
+}
+
+/** Reservation through tracked memory allocator. */
+static int test_reserve(void *baton, void **mem, size_t elm_size, size_t want, size_t *have)
+{
+ if (want > *have) {
+ void *new_mem = mm_alloc(baton, elm_size * want);
+ if (*mem != NULL) {
+ memcpy(new_mem, *mem, (*have) * elm_size);
+ mm_free(baton, *mem);
+ }
+ *mem = new_mem;
+ *have = want;
+ }
+
+ return 0;
+}
+
+/** Reservation through fake memory allocator. */
+static int fake_reserve(void *baton, void **mem, size_t elm_size, size_t want, size_t *have)
+{
+ return -1;
+}
+
+static void test_array_mm(void **state)
+{
+ array_t(int) arr;
+ array_init(arr);
+
+ /* Reserve using fake memory allocator. */
+ assert_false(array_reserve_mm(arr, 5, fake_reserve, NULL) >= 0);
+
+ /* Reserve capacity and fill. */
+ assert_true(array_reserve_mm(arr, 100, test_reserve, &global_mm) >= 0);
+ for (unsigned i = 0; i < 100; ++i) {
+ int ret = array_push(arr, i);
+ assert_true(ret >= 0);
+ }
+
+ array_clear_mm(arr, mm_free, &global_mm);
+
+}
+
+int main(void)
+{
+ test_mm_ctx_init(&global_mm);
+
+ const UnitTest tests[] = {
+ unit_test(test_array),
+ unit_test(test_array_mm)
+ };
+
+ return run_tests(tests);
+}
diff --git a/lib/generic/test_lru.c b/lib/generic/test_lru.c
new file mode 100644
index 0000000..5cd4811
--- /dev/null
+++ b/lib/generic/test_lru.c
@@ -0,0 +1,111 @@
+/* Copyright (C) 2014-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tests/unit/test.h"
+#include "lib/generic/lru.h"
+
+typedef lru_t(int) lru_int_t;
+#define HASH_SIZE 1024
+#define KEY_LEN(x) (strlen(x) + 1)
+
+/*
+ * Sample dictionary
+ */
+static const char *dict[] = {
+ "catagmatic", "prevaricator", "statoscope", "workhand", "benzamide",
+ "alluvia", "fanciful", "bladish", "Tarsius", "unfast", "appropriative",
+ "seraphically", "monkeypod", "deflectometer", "tanglesome", "zodiacal",
+ "physiologically", "economizer", "forcepslike", "betrumpet",
+ "Danization", "broadthroat", "randir", "usherette", "nephropyosis",
+ "hematocyanin", "chrysohermidin", "uncave", "mirksome", "podophyllum",
+ "siphonognathous", "indoor", "featheriness", "forwardation",
+ "archruler", "soricoid", "Dailamite", "carmoisin", "controllability",
+ "unpragmatical", "childless", "transumpt", "productive",
+ "thyreotoxicosis", "oversorrow", "disshadow", "osse", "roar",
+ "pantomnesia", "talcer", "hydrorrhoea", "Satyridae", "undetesting",
+ "smoothbored", "widower", "sivathere", "pendle", "saltation",
+ "autopelagic", "campfight", "unexplained", "Macrorhamphosus",
+ "absconsa", "counterflory", "interdependent", "triact", "reconcentration",
+ "oversharpness", "sarcoenchondroma", "superstimulate", "assessory",
+ "pseudepiscopacy", "telescopically", "ventriloque", "politicaster",
+ "Caesalpiniaceae", "inopportunity", "Helion", "uncompatible",
+ "cephaloclasia", "oversearch", "Mahayanistic", "quarterspace",
+ "bacillogenic", "hamartite", "polytheistical", "unescapableness",
+ "Pterophorus", "cradlemaking", "Hippoboscidae", "overindustrialize",
+ "perishless", "cupidity", "semilichen", "gadge", "detrimental",
+ "misencourage", "toparchia", "lurchingly", "apocatastasis"
+};
+
+static void test_insert(void **state)
+{
+ lru_int_t *lru = *state;
+ int dict_size = sizeof(dict) / sizeof(const char *);
+ int i;
+
+ for (i = 0; i < dict_size; i++) {
+ int *data = lru_get_new(lru, dict[i], KEY_LEN(dict[i]), NULL);
+ if (!data) {
+ continue;
+ }
+ *data = i;
+ assert_true(*lru_get_try(lru, dict[i], KEY_LEN(dict[i])) == i);
+ }
+}
+
+static void test_missing(void **state)
+{
+ lru_int_t *lru = *state;
+ const char *notin = "not in lru";
+ assert_true(lru_get_try(lru, notin, KEY_LEN(notin)) == NULL);
+}
+
+static void test_eviction(void **state)
+{
+ lru_int_t *lru = *state;
+ char key[16];
+ for (unsigned i = 0; i < HASH_SIZE; ++i) {
+ test_randstr(key, sizeof(key));
+ int *data = lru_get_new(lru, key, sizeof(key), NULL);
+ if (!data) {
+ continue;
+ }
+ *data = i;
+ if (*lru_get_try(lru, key, sizeof(key)) != i) {
+ assert_true(0);
+ }
+ }
+}
+
+static void test_init(void **state)
+{
+ lru_int_t *lru;
+ lru_create(&lru, HASH_SIZE, NULL, NULL);
+ assert_non_null(lru);
+ *state = lru;
+}
+
+static void test_deinit(void **state)
+{
+ lru_int_t *lru = *state;
+ lru_free(lru);
+}
+
+/* Program entry point */
+int main(int argc, char **argv)
+{
+ const UnitTest tests[] = {
+ group_test_setup(test_init),
+ unit_test(test_insert),
+ unit_test(test_missing),
+ unit_test(test_eviction),
+ group_test_teardown(test_deinit)
+ };
+
+ return run_group_tests(tests);
+}
diff --git a/lib/generic/test_map.c b/lib/generic/test_map.c
new file mode 100644
index 0000000..7a04bfe
--- /dev/null
+++ b/lib/generic/test_map.c
@@ -0,0 +1,119 @@
+/* Copyright (C) 2014-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tests/unit/test.h"
+#include "lib/generic/map.h"
+
+/*
+ * Sample dictionary
+ */
+static const char *dict[] = {
+ "catagmatic", "prevaricator", "statoscope", "workhand", "benzamide",
+ "alluvia", "fanciful", "bladish", "Tarsius", "unfast", "appropriative",
+ "seraphically", "monkeypod", "deflectometer", "tanglesome", "zodiacal",
+ "physiologically", "economizer", "forcepslike", "betrumpet",
+ "Danization", "broadthroat", "randir", "usherette", "nephropyosis",
+ "hematocyanin", "chrysohermidin", "uncave", "mirksome", "podophyllum",
+ "siphonognathous", "indoor", "featheriness", "forwardation",
+ "archruler", "soricoid", "Dailamite", "carmoisin", "controllability",
+ "unpragmatical", "childless", "transumpt", "productive",
+ "thyreotoxicosis", "oversorrow", "disshadow", "osse", "roar",
+ "pantomnesia", "talcer", "hydrorrhoea", "Satyridae", "undetesting",
+ "smoothbored", "widower", "sivathere", "pendle", "saltation",
+ "autopelagic", "campfight", "unexplained", "Macrorhamphosus",
+ "absconsa", "counterflory", "interdependent", "triact", "reconcentration",
+ "oversharpness", "sarcoenchondroma", "superstimulate", "assessory",
+ "pseudepiscopacy", "telescopically", "ventriloque", "politicaster",
+ "Caesalpiniaceae", "inopportunity", "Helion", "uncompatible",
+ "cephaloclasia", "oversearch", "Mahayanistic", "quarterspace",
+ "bacillogenic", "hamartite", "polytheistical", "unescapableness",
+ "Pterophorus", "cradlemaking", "Hippoboscidae", "overindustrialize",
+ "perishless", "cupidity", "semilichen", "gadge", "detrimental",
+ "misencourage", "toparchia", "lurchingly", "apocatastasis"
+};
+
+/* Insertions */
+static void test_insert(void **state)
+{
+ map_t *tree = *state;
+ int dict_size = sizeof(dict) / sizeof(const char *);
+ int i;
+
+ for (i = 0; i < dict_size; i++) {
+ assert_int_equal(map_set(tree, dict[i], (void *)dict[i]), 0);
+ }
+}
+
+/* Searching */
+static void test_get(void **state)
+{
+ map_t *tree = *state;
+ char *in;
+ const char *notin = "not in tree";
+
+ in = malloc(strlen(dict[23])+1);
+ strcpy(in, dict[23]);
+
+ assert_true(map_get(tree, in) == dict[23]);
+ assert_true(map_get(tree, notin) == NULL);
+ assert_true(map_get(tree, "") == NULL);
+ in[strlen(in)/2] = '\0';
+ assert_true(map_get(tree, in) == NULL);
+
+ free(in);
+}
+
+/* Deletion */
+static void test_delete(void **state)
+{
+ map_t *tree = *state;
+ assert_int_equal(map_del(tree, dict[91]), 0);
+ assert_false(map_contains(tree, dict[91]));
+ assert_int_equal(map_del(tree, "most likely not in tree"), 1);
+}
+
+/* Test null value existence */
+static void test_null_value(void **state)
+{
+ map_t *tree = *state;
+ char *key = "foo";
+
+ assert_int_equal(map_set(tree, key, (void *)0), 0);
+ assert_true(map_contains(tree, key));
+ assert_int_equal(map_del(tree, key), 0);
+}
+
+static void test_init(void **state)
+{
+ static map_t tree;
+ tree = map_make(NULL);
+ *state = &tree;
+ assert_non_null(*state);
+}
+
+static void test_deinit(void **state)
+{
+ map_t *tree = *state;
+ map_clear(tree);
+}
+
+/* Program entry point */
+int main(int argc, char **argv)
+{
+ const UnitTest tests[] = {
+ group_test_setup(test_init),
+ unit_test(test_insert),
+ unit_test(test_get),
+ unit_test(test_delete),
+ unit_test(test_null_value),
+ group_test_teardown(test_deinit)
+ };
+
+ return run_group_tests(tests);
+}
diff --git a/lib/generic/test_pack.c b/lib/generic/test_pack.c
new file mode 100644
index 0000000..f25c199
--- /dev/null
+++ b/lib/generic/test_pack.c
@@ -0,0 +1,70 @@
+/* Copyright (C) 2015-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "tests/unit/test.h"
+#include "lib/generic/pack.h"
+
+#define U8(x) (const uint8_t *)(x)
+knot_mm_t global_mm;
+
+static void test_pack_std(void **state)
+{
+ int ret = 0;
+ pack_t pack;
+ pack_init(pack);
+ assert_int_equal(pack.len, 0);
+
+ /* Test that iterator on empty pack works */
+ assert_null(pack_head(pack));
+ assert_null(pack_tail(pack));
+ assert_null(pack_obj_find(&pack, U8(""), 1));
+ assert_int_equal(pack_obj_len(pack_head(pack)), 0);
+ assert_int_equal(pack_obj_del(&pack, U8(""), 1), -1);
+
+ /* Push/delete without reservation. */
+ assert_int_not_equal(pack_obj_push(&pack, U8(""), 1), 0);
+ assert_int_not_equal(pack_obj_del(&pack, U8(""), 1), 0);
+
+ /* Reserve capacity and fill. */
+ assert_true(pack_reserve(pack, 10, 10 * 2) >= 0);
+ for (unsigned i = 0; i < 10; ++i) {
+ ret = pack_obj_push(&pack, U8("de"), 2);
+ assert_true(ret >= 0);
+ }
+
+ /* Iterate */
+ uint8_t *it = pack_head(pack);
+ assert_non_null(it);
+ unsigned count = 0;
+ while (it != pack_tail(pack)) {
+ assert_int_equal(pack_obj_len(it), 2);
+ assert_true(memcmp(pack_obj_val(it), "de", 2) == 0);
+ it = pack_obj_next(it);
+ count += 1;
+ }
+
+ /* Find */
+ it = pack_obj_find(&pack, U8("de"), 2);
+ assert_non_null(it);
+ it = pack_obj_find(&pack, U8("ed"), 2);
+ assert_null(it);
+
+ /* Delete */
+ assert_int_not_equal(pack_obj_del(&pack, U8("be"), 2), 0);
+ assert_int_equal(pack_obj_del(&pack, U8("de"), 2), 0);
+ assert_int_equal(pack.len, 9*(2+2)); /* 9 objects, length=2 */
+
+ pack_clear(pack);
+}
+
+int main(void)
+{
+ test_mm_ctx_init(&global_mm);
+
+ const UnitTest tests[] = {
+ unit_test(test_pack_std),
+ };
+
+ return run_tests(tests);
+}
diff --git a/lib/generic/test_queue.c b/lib/generic/test_queue.c
new file mode 100644
index 0000000..3a6b5be
--- /dev/null
+++ b/lib/generic/test_queue.c
@@ -0,0 +1,71 @@
+/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "tests/unit/test.h"
+#include "lib/generic/queue.h"
+
+/* The main intention is to use queues with pointers, so we test the same-sized int. */
+typedef queue_t(ptrdiff_t) queue_int_t;
+typedef queue_it_t(int) queue_int_it_t;
+
+static void test_int(void **state_)
+{
+ queue_int_t q;
+ queue_init(q);
+
+ /* Case of emptying the queue (and using again) has been broken for a long time. */
+ queue_push(q, 2);
+ queue_pop(q);
+ queue_push(q, 4);
+ queue_pop(q);
+
+ queue_push_head(q, 2);
+ queue_push_head(q, 1);
+ queue_push_head(q, 0);
+ for (int i = 0; i < 100; ++i) {
+ assert_int_equal(queue_head(q), i);
+ queue_push(q, i + 3);
+ queue_pop(q);
+ }
+ assert_int_equal(queue_len(q), 3);
+ for (int i = 99; i > 0; --i) {
+ assert_int_equal(queue_head(q), i + 1);
+ queue_push_head(q, i);
+ }
+ assert_int_equal(queue_len(q), 3 + 99);
+
+ /* Basic iterator test. */
+ {
+ int i = 0;
+ for (queue_int_it_t it = queue_it_begin(q); !queue_it_finished(it);
+ queue_it_next(it)) {
+ ++queue_it_val(it);
+ ++i;
+ }
+ assert_int_equal(queue_len(q), i);
+ }
+
+ queue_deinit(q);
+ queue_init(q);
+
+ for (int i = 0; i < 100; ++i) {
+ queue_push(q, 2*i);
+ queue_push(q, 2*i + 1);
+ assert_int_equal(queue_head(q), i);
+ queue_pop(q);
+ }
+
+ queue_deinit(q);
+}
+
+
+int main(void)
+{
+ const UnitTest tests[] = {
+ unit_test(test_int),
+ };
+
+ return run_tests(tests);
+}
+
diff --git a/lib/generic/test_set.c b/lib/generic/test_set.c
new file mode 100644
index 0000000..adb5222
--- /dev/null
+++ b/lib/generic/test_set.c
@@ -0,0 +1,221 @@
+/*
+ * critbit89 - A crit-bit tree implementation for strings in C89
+ * Written by Jonas Gehring <jonas@jgehring.net>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tests/unit/test.h"
+#include "lib/generic/set.h"
+#include "lib/utils.h"
+
+
+/*
+ * Sample dictionary: 100 random words from /usr/share/dict/words
+ * Generated using random.org:
+ * MAX=`wc -l < /usr/share/dict/words | tr -d " "`
+ * for i in `curl "http://www.random.org/integers/?num=100&min=1&max=$MAX&col=1&base=10&format=plain&rnd=new"`; do
+ * nl /usr/share/dict/words | grep -w $i | tr -d "0-9\t "
+ * done
+ */
+static const char *dict[] = {
+ "catagmatic", "prevaricator", "statoscope", "workhand", "benzamide",
+ "alluvia", "fanciful", "bladish", "Tarsius", "unfast", "appropriative",
+ "seraphically", "monkeypod", "deflectometer", "tanglesome", "zodiacal",
+ "physiologically", "economizer", "forcepslike", "betrumpet",
+ "Danization", "broadthroat", "randir", "usherette", "nephropyosis",
+ "hematocyanin", "chrysohermidin", "uncave", "mirksome", "podophyllum",
+ "siphonognathous", "indoor", "featheriness", "forwardation",
+ "archruler", "soricoid", "Dailamite", "carmoisin", "controllability",
+ "unpragmatical", "childless", "transumpt", "productive",
+ "thyreotoxicosis", "oversorrow", "disshadow", "osse", "roar",
+ "pantomnesia", "talcer", "hydrorrhoea", "Satyridae", "undetesting",
+ "smoothbored", "widower", "sivathere", "pendle", "saltation",
+ "autopelagic", "campfight", "unexplained", "Macrorhamphosus",
+ "absconsa", "counterflory", "interdependent", "triact", "reconcentration",
+ "oversharpness", "sarcoenchondroma", "superstimulate", "assessory",
+ "pseudepiscopacy", "telescopically", "ventriloque", "politicaster",
+ "Caesalpiniaceae", "inopportunity", "Helion", "uncompatible",
+ "cephaloclasia", "oversearch", "Mahayanistic", "quarterspace",
+ "bacillogenic", "hamartite", "polytheistical", "unescapableness",
+ "Pterophorus", "cradlemaking", "Hippoboscidae", "overindustrialize",
+ "perishless", "cupidity", "semilichen", "gadge", "detrimental",
+ "misencourage", "toparchia", "lurchingly", "apocatastasis"
+};
+
+/* Insertions */
+static void test_insert(void **state)
+{
+ set_t *set = *state;
+ int dict_size = sizeof(dict) / sizeof(const char *);
+ int i;
+
+ for (i = 0; i < dict_size; i++) {
+ assert_int_equal(set_add(set, dict[i]), 0);
+ }
+}
+
+/* Insertion of duplicate element */
+static void test_insert_dup(void **state)
+{
+ set_t *set = *state;
+ int dict_size = sizeof(dict) / sizeof(const char *);
+ int i;
+
+ for (i = 0; i < dict_size; i++) {
+ if (!set_contains(set, dict[i])) {
+ continue;
+ }
+ assert_int_equal(set_add(set, dict[i]), 1);
+ }
+}
+
+/* Searching */
+static void test_contains(void **state)
+{
+ set_t *set = *state;
+ char *in;
+ const char *notin = "not in set";
+
+ in = malloc(strlen(dict[23])+1);
+ strcpy(in, dict[23]);
+
+ assert_true(set_contains(set, in));
+ assert_false(set_contains(set, notin));
+ assert_false(set_contains(set, ""));
+ in[strlen(in)/2] = '\0';
+ assert_false(set_contains(set, in));
+
+ free(in);
+}
+
+/* Count number of items */
+static int count_cb(const char *s, void *_, void *n) { (*(int *)n)++; return 0; }
+static void test_complete(set_t *set, int n)
+{
+ int i = 0;
+ if (set_walk(set, count_cb, &i) != 0) {
+ abort();
+ }
+ if (i != n) {
+ abort();
+ }
+}
+static void test_complete_full(void **state) { test_complete(*state, sizeof(dict) / sizeof(const char *)); }
+static void test_complete_zero(void **state) { test_complete(*state, 0); }
+
+/* Deletion */
+static void test_delete(void **state)
+{
+ set_t *set = *state;
+ assert_int_equal(set_del(set, dict[91]), 0);
+ assert_int_equal(set_del(set, "most likely not in set"), 1);
+}
+
+/* Complete deletion */
+static void test_delete_all(void **state)
+{
+ set_t *set = *state;
+ int dict_size = sizeof(dict) / sizeof(const char *);
+ int i;
+
+ for (i = 0; i < dict_size; i++) {
+ if (!set_contains(set, dict[i])) {
+ continue;
+ }
+ assert_int_equal(set_del(set, dict[i]), 0);
+ }
+}
+
+/* Fake allocator */
+static void *fake_malloc(void *b, size_t s) { return NULL; }
+static void test_allocator(void **state)
+{
+ knot_mm_t fake_pool = { .ctx = NULL, .alloc = fake_malloc, .free = NULL };
+ set_t set = set_make(&fake_pool);
+ assert_int_equal(set_add(&set, dict[0]), ENOMEM);
+}
+
+/* Empty set */
+static void test_empty(void **state)
+{
+ set_t *set = *state;
+ assert_int_equal(set_contains(set, dict[1]), 0);
+ assert_int_not_equal(set_del(set, dict[1]), 0);
+}
+
+/* Prefix walking */
+static void test_prefixes(void **state)
+{
+ set_t *set = *state;
+ int i = 0;
+ if ((set_add(set, "1str") != 0) ||
+ (set_add(set, "11str2") != 0) ||
+ (set_add(set, "12str") != 0) ||
+ (set_add(set, "11str") != 0)) {
+ assert_int_equal(1, 0);
+ }
+
+ assert_int_equal(set_walk_prefixed(set, "11", count_cb, &i), 0);
+ assert_int_equal(i, 2);
+ i = 0;
+ assert_int_equal(set_walk_prefixed(set, "13", count_cb, &i), 0);
+ assert_int_equal(i, 0);
+ i = 0;
+ assert_int_equal(set_walk_prefixed(set, "12345678", count_cb, &i), 0);
+ assert_int_equal(i, 0);
+ i = 0;
+ assert_int_equal(set_walk_prefixed(set, "11str", count_cb, &i), 0);
+ assert_int_equal(i, 2);
+}
+
+static void test_clear(void **state)
+{
+ set_t *set = *state;
+ set_clear(set);
+}
+
+static void test_init(void **state)
+{
+ static set_t set;
+ set = set_make(NULL);
+ *state = &set;
+ assert_non_null(*state);
+}
+
+static void test_deinit(void **state)
+{
+ set_t *set = *state;
+ set_clear(set);
+}
+
+/* Program entry point */
+int main(int argc, char **argv)
+{
+ const UnitTest tests[] = {
+ group_test_setup(test_init),
+ unit_test(test_insert),
+ unit_test(test_complete_full),
+ unit_test(test_insert_dup),
+ unit_test(test_contains),
+ unit_test(test_delete),
+ unit_test(test_clear),
+ unit_test(test_insert),
+ unit_test(test_complete_full),
+ unit_test(test_delete_all),
+ unit_test(test_complete_zero),
+ unit_test(test_allocator),
+ unit_test(test_clear),
+ unit_test(test_empty),
+ unit_test(test_insert),
+ unit_test(test_prefixes),
+ group_test_teardown(test_deinit)
+ };
+
+ return run_group_tests(tests);
+}
diff --git a/lib/generic/test_trie.c b/lib/generic/test_trie.c
new file mode 100644
index 0000000..6740948
--- /dev/null
+++ b/lib/generic/test_trie.c
@@ -0,0 +1,154 @@
+/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "lib/generic/trie.h"
+#include "tests/unit/test.h"
+
+static const char *dict[] = {
+ "catagmatic", "prevaricator", "statoscope", "workhand", "benzamide",
+ "work", "workhands", // have some keys that are prefixes of each other
+ "alluvia", "fanciful", "bladish", "Tarsius", "unfast", "appropriative",
+ "seraphically", "monkeypod", "deflectometer", "tanglesome", "zodiacal",
+ "physiologically", "economizer", "forcepslike", "betrumpet",
+ "Danization", "broadthroat", "randir", "usherette", "nephropyosis",
+ "hematocyanin", "chrysohermidin", "uncave", "mirksome", "podophyllum",
+ "siphonognathous", "indoor", "featheriness", "forwardation",
+ "archruler", "soricoid", "Dailamite", "carmoisin", "controllability",
+ "unpragmatical", "childless", "transumpt", "productive",
+ "thyreotoxicosis", "oversorrow", "disshadow", "osse", "roar",
+ "pantomnesia", "talcer", "hydrorrhoea", "Satyridae", "undetesting",
+ "smoothbored", "widower", "sivathere", "pendle", "saltation",
+ "autopelagic", "campfight", "unexplained", "Macrorhamphosus",
+ "absconsa", "counterflory", "interdependent", "triact", "reconcentration",
+ "oversharpness", "sarcoenchondroma", "superstimulate", "assessory",
+ "pseudepiscopacy", "telescopically", "ventriloque", "politicaster",
+ "Caesalpiniaceae", "inopportunity", "Helion", "uncompatible",
+ "cephaloclasia", "oversearch", "Mahayanistic", "quarterspace",
+ "bacillogenic", "hamartite", "polytheistical", "unescapableness",
+ "Pterophorus", "cradlemaking", "Hippoboscidae", "overindustrialize",
+ "perishless", "cupidity", "semilichen", "gadge", "detrimental",
+ "misencourage", "toparchia", "lurchingly", "apocatastasis"
+};
+#define KEY_LEN(x) (strlen(x) + 1)
+static const int dict_size = sizeof(dict) / sizeof(const char *);
+
+static void test_init(void **state)
+{
+ trie_t *t = trie_create(NULL);
+ assert_non_null(t);
+ *state = t;
+}
+
+static void test_insert(void **state)
+{
+ trie_t *t = *state;
+
+ for (int i = 0; i < dict_size; ++i) {
+ trie_val_t *data = trie_get_ins(t, dict[i], KEY_LEN(dict[i]));
+ assert_non_null(data);
+ assert_null(*data);
+ *data = (char *)NULL + i; // yes, ugly
+ assert_ptr_equal(trie_get_try(t, dict[i], KEY_LEN(dict[i])), data);
+ }
+ assert_int_equal(trie_weight(t), dict_size);
+}
+
+static void test_missing(void **state)
+{
+ trie_t *t = *state;
+ const char *notin = "p";
+ assert_null(trie_get_try(t, notin, KEY_LEN(notin)));
+}
+
+static int cmpstringp(const void *p1, const void *p2)
+{
+ return strcmp(* (char * const *) p1, * (char * const *) p2);
+}
+
+static void test_iter(void **state)
+{
+ // prepare sorted dictionary
+ char *dict_sorted[dict_size];
+ memcpy(dict_sorted, dict, sizeof(dict));
+ qsort(dict_sorted, dict_size, sizeof(dict[0]), cmpstringp);
+
+ // iterate and check the order is consistent
+ trie_t *t = *state;
+ trie_it_t *it = trie_it_begin(t);
+ for (int i = 0; i < dict_size; ++i, trie_it_next(it)) {
+ assert_false(trie_it_finished(it));
+ size_t len;
+ const char *key = trie_it_key(it, &len);
+ assert_int_equal(KEY_LEN(key), len);
+ assert_string_equal(key, dict_sorted[i]);
+ assert_ptr_equal(dict[(char *)*trie_it_val(it) - (char *)NULL],
+ dict_sorted[i]);
+ }
+ assert_true(trie_it_finished(it));
+ trie_it_free(it);
+}
+
+static void test_queue(void **state)
+{
+ trie_t *t = *state;
+ // remove all the elements in ascending order
+ for (int i = 0; i < dict_size; ++i) {
+ char *key;
+ uint32_t len;
+ trie_val_t *data = trie_get_first(t, &key, &len);
+ assert_non_null(key);
+ assert_int_equal(len, KEY_LEN(key));
+ assert_non_null(data);
+ ptrdiff_t key_i = (char *)*data - (char *)NULL;
+ assert_string_equal(key, dict[key_i]);
+
+ len = 30;
+ char key_buf[len];
+ ptrdiff_t key_i_new;
+ int ret = trie_del_first(t, key_buf, &len, (trie_val_t *)&key_i_new);
+ assert_int_equal(ret, kr_ok());
+ assert_int_equal(KEY_LEN(key_buf), len);
+ assert_int_equal(key_i, key_i_new);
+ assert_string_equal(dict[key_i], key_buf);
+ }
+}
+
+static void test_leq_bug(void **state)
+{
+ /* We use different contents of the trie,
+ * so that the particular bug would've been triggered. */
+ trie_t *t = trie_create(NULL);
+ char key = 'a';
+ trie_get_ins(t, &key, sizeof(key));
+
+ key = (char)0xff;
+ trie_val_t *val;
+ int ret = trie_get_leq(t, &key, sizeof(key), &val);
+ assert_int_equal(ret, 1);
+ trie_free(t);
+}
+
+static void test_deinit(void **state)
+{
+ trie_t *t = *state;
+ trie_free(t);
+ *state = NULL;
+}
+
+/* Program entry point */
+int main(int argc, char **argv)
+{
+ const UnitTest tests[] = {
+ group_test_setup(test_init),
+ unit_test(test_insert),
+ unit_test(test_leq_bug),
+ unit_test(test_missing),
+ unit_test(test_iter),
+ unit_test(test_queue),
+ group_test_teardown(test_deinit)
+ };
+
+ return run_group_tests(tests);
+}
+
diff --git a/lib/generic/trie.c b/lib/generic/trie.c
new file mode 100644
index 0000000..682b159
--- /dev/null
+++ b/lib/generic/trie.c
@@ -0,0 +1,900 @@
+/* Copyright (C) 2016-2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+
+ The code originated from https://github.com/fanf2/qp/blob/master/qp.c
+ at revision 5f6d93753.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lib/generic/trie.h"
+#include "lib/utils.h"
+#include "contrib/ucw/lib.h"
+
+#if defined(__i386) || defined(__x86_64) || defined(_M_IX86) \
+ || (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN) \
+ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+
+ /*!
+ * \brief Use a pointer alignment hack to save memory.
+ *
+ * When on, isbranch() relies on the fact that in leaf_t the first pointer
+ * is aligned on multiple of 4 bytes and that the flags bitfield is
+ * overlaid over the lowest two bits of that pointer.
+ * Neither is really guaranteed by the C standards; the second part should
+ * be OK with x86_64 ABI and most likely any other little-endian platform.
+ * It would be possible to manipulate the right bits portably, but it would
+ * complicate the code nontrivially. C++ doesn't even guarantee type-punning.
+ * In debug mode we check this works OK when creating a new trie instance.
+ */
+ #define FLAGS_HACK 1
+#else
+ #define FLAGS_HACK 0
+#endif
+
+typedef unsigned char byte;
+#ifndef uint
+typedef unsigned int uint;
+#define uint uint
+#endif
+typedef uint bitmap_t; /*! Bit-maps, using the range of 1<<0 to 1<<16 (inclusive). */
+
+typedef struct {
+ uint32_t len; // 32 bits are enough for key lengths; probably even 16 bits would be.
+ char chars[];
+} tkey_t;
+
+/*! \brief Leaf of trie. */
+typedef struct {
+ #if !FLAGS_HACK
+ byte flags;
+ #endif
+ tkey_t *key; /*!< The pointer must be aligned to 4-byte multiples! */
+ trie_val_t val;
+} leaf_t;
+
+/*! \brief A trie node is either leaf_t or branch_t. */
+typedef union node node_t;
+
+/*!
+ * \brief Branch node of trie.
+ *
+ * - The flags distinguish whether the node is a leaf_t (0), or a branch
+ * testing the more-important nibble (1) or the less-important one (2).
+ * - It stores the index of the byte that the node tests. The combined
+ * value (index*4 + flags) increases in branch nodes as you go deeper
+ * into the trie. All the keys below a branch are identical up to the
+ * nibble identified by the branch. Indices have to be stored because
+ * we skip any branch nodes that would have a single child.
+ * (Consequently, the skipped parts of key have to be validated in a leaf.)
+ * - The bitmap indicates which subtries are present. The present child nodes
+ * are stored in the twigs array (with no holes between them).
+ * - To simplify storing keys that are prefixes of each other, the end-of-string
+ * position is treated as another nibble value, ordered before all others.
+ * That affects the bitmap and twigs fields.
+ *
+ * \note The branch nodes are never allocated individually, but they are
+ * always part of either the root node or the twigs array of the parent.
+ */
+typedef struct {
+ #if FLAGS_HACK
+ uint32_t flags : 2,
+ bitmap : 17; /*!< The first bitmap bit is for end-of-string child. */
+ #else
+ byte flags;
+ uint32_t bitmap;
+ #endif
+ uint32_t index;
+ node_t *twigs;
+} branch_t;
+
+union node {
+ leaf_t leaf;
+ branch_t branch;
+};
+
+struct trie {
+ node_t root; // undefined when weight == 0, see empty_root()
+ size_t weight;
+ knot_mm_t mm;
+};
+
+/*! \brief Make the root node empty (debug-only). */
+static inline void empty_root(node_t *root) {
+#ifndef NDEBUG
+ *root = (node_t){ .branch = {
+ .flags = 3, // invalid value that fits
+ .bitmap = 0,
+ .index = -1,
+ .twigs = NULL
+ } };
+#endif
+}
+
+/*! \brief Check that unportable code works OK (debug-only). */
+static void assert_portability(void) {
+#if FLAGS_HACK
+ assert(((union node){ .leaf = {
+ .key = (tkey_t *)(((uint8_t *)NULL) + 1),
+ .val = NULL
+ } }).branch.flags == 1);
+#endif
+}
+
+/*! \brief Propagate error codes. */
+#define ERR_RETURN(x) \
+ do { \
+ int err_code_ = x; \
+ if (unlikely(err_code_ != KNOT_EOK)) \
+ return err_code_; \
+ } while (false)
+
+/*!
+ * \brief Count the number of set bits.
+ *
+ * \TODO This implementation may be relatively slow on some HW.
+ */
+static uint bitmap_weight(bitmap_t w)
+{
+ assert((w & ~((1 << 17) - 1)) == 0); // using the least-important 17 bits
+ return __builtin_popcount(w);
+}
+
+/*! \brief Only keep the lowest bit in the bitmap (least significant -> twigs[0]). */
+static bitmap_t bitmap_lowest_bit(bitmap_t w)
+{
+ assert((w & ~((1 << 17) - 1)) == 0); // using the least-important 17 bits
+ return 1 << __builtin_ctz(w);
+}
+
+/*! \brief Test flags to determine type of this node. */
+static bool isbranch(const node_t *t)
+{
+ uint f = t->branch.flags;
+ assert(f <= 2);
+ return f != 0;
+}
+
+/*! \brief Make a bitmask for testing a branch bitmap. */
+static bitmap_t nibbit(byte k, uint flags)
+{
+ uint shift = (2 - flags) << 2;
+ uint nibble = (k >> shift) & 0xf;
+ return 1 << (nibble + 1/*because of prefix keys*/);
+}
+
+/*! \brief Extract a nibble from a key and turn it into a bitmask. */
+static bitmap_t twigbit(const node_t *t, const char *key, uint32_t len)
+{
+ assert(isbranch(t));
+ uint i = t->branch.index;
+
+ if (i >= len)
+ return 1 << 0; // leaf position
+
+ return nibbit((byte)key[i], t->branch.flags);
+}
+
+/*! \brief Test if a branch node has a child indicated by a bitmask. */
+static bool hastwig(const node_t *t, bitmap_t bit)
+{
+ assert(isbranch(t));
+ return t->branch.bitmap & bit;
+}
+
+/*! \brief Compute offset of an existing child in a branch node. */
+static uint twigoff(const node_t *t, bitmap_t b)
+{
+ assert(isbranch(t));
+ return bitmap_weight(t->branch.bitmap & (b - 1));
+}
+
+/*! \brief Get pointer to a particular child of a branch node. */
+static node_t* twig(node_t *t, uint i)
+{
+ assert(isbranch(t));
+ return &t->branch.twigs[i];
+}
+
+/*!
+ * \brief For a branch nod, compute offset of a child and child count.
+ *
+ * Having this separate might be meaningful for performance optimization.
+ */
+#define TWIGOFFMAX(off, max, t, b) do { \
+ (off) = twigoff((t), (b)); \
+ (max) = bitmap_weight((t)->branch.bitmap);\
+ } while(0)
+
+/*! \brief Simple string comparator. */
+static int key_cmp(const char *k1, uint32_t k1_len, const char *k2, uint32_t k2_len)
+{
+ int ret = memcmp(k1, k2, MIN(k1_len, k2_len));
+ if (ret != 0) {
+ return ret;
+ }
+
+ /* Key string is equal, compare lengths. */
+ if (k1_len == k2_len) {
+ return 0;
+ } else if (k1_len < k2_len) {
+ return -1;
+ } else {
+ return 1;
+ }
+}
+
+trie_t* trie_create(knot_mm_t *mm)
+{
+ assert_portability();
+ trie_t *trie = mm_alloc(mm, sizeof(trie_t));
+ if (trie != NULL) {
+ empty_root(&trie->root);
+ trie->weight = 0;
+ if (mm != NULL)
+ trie->mm = *mm;
+ else
+ mm_ctx_init(&trie->mm);
+ }
+ return trie;
+}
+
+/*! \brief Free anything under the trie node, except for the passed pointer itself. */
+static void clear_trie(node_t *trie, knot_mm_t *mm)
+{
+ if (!isbranch(trie)) {
+ mm_free(mm, trie->leaf.key);
+ } else {
+ branch_t *b = &trie->branch;
+ int len = bitmap_weight(b->bitmap);
+ for (int i = 0; i < len; ++i)
+ clear_trie(b->twigs + i, mm);
+ mm_free(mm, b->twigs);
+ }
+}
+
+void trie_free(trie_t *tbl)
+{
+ if (tbl == NULL)
+ return;
+ if (tbl->weight)
+ clear_trie(&tbl->root, &tbl->mm);
+ mm_free(&tbl->mm, tbl);
+}
+
+void trie_clear(trie_t *tbl)
+{
+ assert(tbl);
+ if (!tbl->weight)
+ return;
+ clear_trie(&tbl->root, &tbl->mm);
+ empty_root(&tbl->root);
+ tbl->weight = 0;
+}
+
+size_t trie_weight(const trie_t *tbl)
+{
+ assert(tbl);
+ return tbl->weight;
+}
+
+struct found {
+ leaf_t *l; /**< the found leaf (NULL if not found) */
+ branch_t *p; /**< the leaf's parent (if exists) */
+ bitmap_t b; /**< bit-mask with a single bit marking l under p */
+};
+/** Search trie for an item with the given key (equality only). */
+static struct found find_equal(trie_t *tbl, const char *key, uint32_t len)
+{
+ assert(tbl);
+ struct found ret0;
+ memset(&ret0, 0, sizeof(ret0));
+ if (!tbl->weight)
+ return ret0;
+ /* Current node and parent while descending (returned values basically). */
+ node_t *t = &tbl->root;
+ branch_t *p = NULL;
+ bitmap_t b = 0;
+ while (isbranch(t)) {
+ __builtin_prefetch(t->branch.twigs);
+ b = twigbit(t, key, len);
+ if (!hastwig(t, b))
+ return ret0;
+ p = &t->branch;
+ t = twig(t, twigoff(t, b));
+ }
+ if (key_cmp(key, len, t->leaf.key->chars, t->leaf.key->len) != 0)
+ return ret0;
+ return (struct found) {
+ .l = &t->leaf,
+ .p = p,
+ .b = b,
+ };
+}
+/** Find item with the first key (lexicographical order). */
+static struct found find_first(trie_t *tbl)
+{
+ assert(tbl);
+ if (!tbl->weight) {
+ struct found ret0;
+ memset(&ret0, 0, sizeof(ret0));
+ return ret0;
+ }
+ /* Current node and parent while descending (returned values basically). */
+ node_t *t = &tbl->root;
+ branch_t *p = NULL;
+ while (isbranch(t)) {
+ p = &t->branch;
+ t = &p->twigs[0];
+ }
+ return (struct found) {
+ .l = &t->leaf,
+ .p = p,
+ .b = p ? bitmap_lowest_bit(p->bitmap) : 0,
+ };
+}
+
+trie_val_t* trie_get_try(trie_t *tbl, const char *key, uint32_t len)
+{
+ struct found found = find_equal(tbl, key, len);
+ return found.l ? &found.l->val : NULL;
+}
+
+trie_val_t* trie_get_first(trie_t *tbl, char **key, uint32_t *len)
+{
+ struct found found = find_first(tbl);
+ if (!found.l)
+ return NULL;
+ if (key)
+ *key = found.l->key->chars;
+ if (len)
+ *len = found.l->key->len;
+ return &found.l->val;
+}
+
+/** Delete the found element (if any) and return value (unless NULL is passed) */
+static int del_found(trie_t *tbl, struct found found, trie_val_t *val)
+{
+ if (!found.l)
+ return KNOT_ENOENT;
+ mm_free(&tbl->mm, found.l->key);
+ if (val != NULL)
+ *val = found.l->val; // we return trie_val_t directly when deleting
+ --tbl->weight;
+ branch_t * const p = found.p; // short-hand
+ if (unlikely(!p)) { // whole trie was a single leaf
+ assert(tbl->weight == 0);
+ empty_root(&tbl->root);
+ return KNOT_EOK;
+ }
+ // remove leaf t as child of p; get child index via pointer arithmetic
+ int ci = ((union node *)found.l) - p->twigs,
+ cc = bitmap_weight(p->bitmap); // child count
+ assert(ci >= 0 && ci < cc);
+
+ if (cc == 2) { // collapse binary node p: move the other child to this node
+ node_t *twigs = p->twigs;
+ (*(union node *)p) = twigs[1 - ci]; // it might be a leaf or branch
+ mm_free(&tbl->mm, twigs);
+ return KNOT_EOK;
+ }
+ memmove(p->twigs + ci, p->twigs + ci + 1, sizeof(node_t) * (cc - ci - 1));
+ p->bitmap &= ~found.b;
+ node_t *twigs = mm_realloc(&tbl->mm, p->twigs, sizeof(node_t) * (cc - 1),
+ sizeof(node_t) * cc);
+ if (likely(twigs != NULL))
+ p->twigs = twigs;
+ /* We can ignore mm_realloc failure, only beware that next time
+ * the prev_size passed to it wouldn't be correct; TODO? */
+ return KNOT_EOK;
+}
+
+int trie_del(trie_t *tbl, const char *key, uint32_t len, trie_val_t *val)
+{
+ struct found found = find_equal(tbl, key, len);
+ return del_found(tbl, found, val);
+}
+
+int trie_del_first(trie_t *tbl, char *key, uint32_t *len, trie_val_t *val)
+{
+ struct found found = find_first(tbl);
+ if (!found.l)
+ return KNOT_ENOENT;
+ if (key) {
+ if (!len)
+ return KNOT_EINVAL;
+ if (*len < found.l->key->len)
+ return kr_error(ENOSPC);
+ memcpy(key, found.l->key->chars, found.l->key->len);
+ }
+ if (len) { // makes sense even with key == NULL
+ *len = found.l->key->len;
+ }
+ return del_found(tbl, found, val);
+}
+
+/*!
+ * \brief Stack of nodes, storing a path down a trie.
+ *
+ * The structure also serves directly as the public trie_it_t type,
+ * in which case it always points to the current leaf, unless we've finished
+ * (i.e. it->len == 0).
+ */
+typedef struct trie_it {
+ node_t* *stack; /*!< The stack; malloc is used directly instead of mm. */
+ uint32_t len; /*!< Current length of the stack. */
+ uint32_t alen; /*!< Allocated/available length of the stack. */
+ /*! \brief Initial storage for \a stack; it should fit in many use cases. */
+ node_t* stack_init[60];
+} nstack_t;
+
+/*! \brief Create a node stack containing just the root (or empty). */
+static void ns_init(nstack_t *ns, trie_t *tbl)
+{
+ assert(tbl);
+ ns->stack = ns->stack_init;
+ ns->alen = sizeof(ns->stack_init) / sizeof(ns->stack_init[0]);
+ if (tbl->weight) {
+ ns->len = 1;
+ ns->stack[0] = &tbl->root;
+ } else {
+ ns->len = 0;
+ }
+}
+
+/*! \brief Free inside of the stack, i.e. not the passed pointer itself. */
+static void ns_cleanup(nstack_t *ns)
+{
+ assert(ns && ns->stack);
+ if (likely(ns->stack == ns->stack_init))
+ return;
+ free(ns->stack);
+ #ifndef NDEBUG
+ ns->stack = NULL;
+ ns->alen = 0;
+ #endif
+}
+
+/*! \brief Allocate more space for the stack. */
+static int ns_longer_alloc(nstack_t *ns)
+{
+ ns->alen *= 2;
+ size_t new_size = sizeof(nstack_t) + ns->alen * sizeof(node_t *);
+ node_t **st;
+ if (ns->stack == ns->stack_init) {
+ st = malloc(new_size);
+ if (st != NULL)
+ memcpy(st, ns->stack, ns->len * sizeof(node_t *));
+ } else {
+ st = realloc(ns->stack, new_size);
+ }
+ if (st == NULL)
+ return KNOT_ENOMEM;
+ ns->stack = st;
+ return KNOT_EOK;
+}
+
+/*! \brief Ensure the node stack can be extended by one. */
+static inline int ns_longer(nstack_t *ns)
+{
+ // get a longer stack if needed
+ if (likely(ns->len < ns->alen))
+ return KNOT_EOK;
+ return ns_longer_alloc(ns); // hand-split the part suitable for inlining
+}
+
+/*!
+ * \brief Find the "branching point" as if searching for a key.
+ *
+ * The whole path to the point is kept on the passed stack;
+ * always at least the root will remain on the top of it.
+ * Beware: the precise semantics of this function is rather tricky.
+ * The top of the stack will contain: the corresponding leaf if exact match is found;
+ * or the immediate node below a branching-point-on-edge or the branching-point itself.
+ *
+ * \param info Set position of the point of first mismatch (in index and flags).
+ * \param first Set the value of the first non-matching character (from trie),
+ * optionally; end-of-string character has value -256 (that's why it's int).
+ * Note: the character is converted to *unsigned* char (i.e. 0..255),
+ * as that's the ordering used in the trie.
+ *
+ * \return KNOT_EOK or KNOT_ENOMEM.
+ */
+static int ns_find_branch(nstack_t *ns, const char *key, uint32_t len,
+ branch_t *info, int *first)
+{
+ assert(ns && ns->len && info);
+ // First find some leaf with longest matching prefix.
+ while (isbranch(ns->stack[ns->len - 1])) {
+ ERR_RETURN(ns_longer(ns));
+ node_t *t = ns->stack[ns->len - 1];
+ __builtin_prefetch(t->branch.twigs);
+ bitmap_t b = twigbit(t, key, len);
+ // Even if our key is missing from this branch we need to
+ // keep iterating down to a leaf. It doesn't matter which
+ // twig we choose since the keys are all the same up to this
+ // index. Note that blindly using twigoff(t, b) can cause
+ // an out-of-bounds index if it equals twigmax(t).
+ uint i = hastwig(t, b) ? twigoff(t, b) : 0;
+ ns->stack[ns->len++] = twig(t, i);
+ }
+ tkey_t *lkey = ns->stack[ns->len-1]->leaf.key;
+ // Find index of the first char that differs.
+ uint32_t index = 0;
+ while (index < MIN(len,lkey->len)) {
+ if (key[index] != lkey->chars[index])
+ break;
+ else
+ ++index;
+ }
+ info->index = index;
+ if (first)
+ *first = lkey->len > index ? (unsigned char)lkey->chars[index] : -256;
+ // Find flags: which half-byte has matched.
+ uint flags;
+ if (index == len && len == lkey->len) { // found equivalent key
+ info->flags = flags = 0;
+ goto success;
+ }
+ if (likely(index < MIN(len,lkey->len))) {
+ byte k2 = (byte)lkey->chars[index];
+ byte k1 = (byte)key[index];
+ flags = ((k1 ^ k2) & 0xf0) ? 1 : 2;
+ } else { // one is prefix of another
+ flags = 1;
+ }
+ info->flags = flags;
+ // now go up the trie from the current leaf
+ branch_t *t;
+ do {
+ if (unlikely(ns->len == 1))
+ goto success; // only the root stays on the stack
+ t = (branch_t*)ns->stack[ns->len - 2];
+ if (t->index < index || (t->index == index && t->flags < flags))
+ goto success;
+ --ns->len;
+ } while (true);
+success:
+ #ifndef NDEBUG // invariants on successful return
+ assert(ns->len);
+ if (isbranch(ns->stack[ns->len - 1])) {
+ t = &ns->stack[ns->len - 1]->branch;
+ assert(t->index > index || (t->index == index && t->flags >= flags));
+ }
+ if (ns->len > 1) {
+ t = &ns->stack[ns->len - 2]->branch;
+ assert(t->index < index || (t->index == index
+ && (t->flags < flags || (t->flags == 1 && flags == 0))));
+ }
+ #endif
+ return KNOT_EOK;
+}
+
+/*!
+ * \brief Advance the node stack to the last leaf in the subtree.
+ *
+ * \return KNOT_EOK or KNOT_ENOMEM.
+ */
+static int ns_last_leaf(nstack_t *ns)
+{
+ assert(ns);
+ do {
+ ERR_RETURN(ns_longer(ns));
+ node_t *t = ns->stack[ns->len - 1];
+ if (!isbranch(t))
+ return KNOT_EOK;
+ int lasti = bitmap_weight(t->branch.bitmap) - 1;
+ assert(lasti >= 0);
+ ns->stack[ns->len++] = twig(t, lasti);
+ } while (true);
+}
+
+/*!
+ * \brief Advance the node stack to the first leaf in the subtree.
+ *
+ * \return KNOT_EOK or KNOT_ENOMEM.
+ */
+static int ns_first_leaf(nstack_t *ns)
+{
+ assert(ns && ns->len);
+ do {
+ ERR_RETURN(ns_longer(ns));
+ node_t *t = ns->stack[ns->len - 1];
+ if (!isbranch(t))
+ return KNOT_EOK;
+ ns->stack[ns->len++] = twig(t, 0);
+ } while (true);
+}
+
+/*!
+ * \brief Advance the node stack to the leaf that is previous to the current node.
+ *
+ * \note Prefix leaf under the current node DOES count (if present; perhaps questionable).
+ * \return KNOT_EOK on success, KNOT_ENOENT on not-found, or possibly KNOT_ENOMEM.
+ */
+static int ns_prev_leaf(nstack_t *ns)
+{
+ assert(ns && ns->len > 0);
+
+ node_t *t = ns->stack[ns->len - 1];
+ if (hastwig(t, 1 << 0)) { // the prefix leaf
+ t = twig(t, 0);
+ ERR_RETURN(ns_longer(ns));
+ ns->stack[ns->len++] = t;
+ return KNOT_EOK;
+ }
+
+ do {
+ if (ns->len < 2)
+ return KNOT_ENOENT; // root without empty key has no previous leaf
+ t = ns->stack[ns->len - 1];
+ node_t *p = ns->stack[ns->len - 2];
+ int pindex = t - p->branch.twigs; // index in parent via pointer arithmetic
+ assert(pindex >= 0 && pindex <= 16);
+ if (pindex > 0) { // t isn't the first child -> go down the previous one
+ ns->stack[ns->len - 1] = twig(p, pindex - 1);
+ return ns_last_leaf(ns);
+ }
+ // we've got to go up again
+ --ns->len;
+ } while (true);
+}
+
+/*!
+ * \brief Advance the node stack to the leaf that is successor to the current node.
+ *
+ * \note Prefix leaf or anything else under the current node DOES count.
+ * \return KNOT_EOK on success, KNOT_ENOENT on not-found, or possibly KNOT_ENOMEM.
+ */
+static int ns_next_leaf(nstack_t *ns)
+{
+ assert(ns && ns->len > 0);
+
+ node_t *t = ns->stack[ns->len - 1];
+ if (isbranch(t))
+ return ns_first_leaf(ns);
+ do {
+ if (ns->len < 2)
+ return KNOT_ENOENT; // not found, as no more parent is available
+ t = ns->stack[ns->len - 1];
+ node_t *p = ns->stack[ns->len - 2];
+ int pindex = t - p->branch.twigs; // index in parent via pointer arithmetic
+ assert(pindex >= 0 && pindex <= 16);
+ int pcount = bitmap_weight(p->branch.bitmap);
+ if (pindex + 1 < pcount) { // t isn't the last child -> go down the next one
+ ns->stack[ns->len - 1] = twig(p, pindex + 1);
+ return ns_first_leaf(ns);
+ }
+ // we've got to go up again
+ --ns->len;
+ } while (true);
+}
+
+int trie_get_leq(trie_t *tbl, const char *key, uint32_t len, trie_val_t **val)
+{
+ assert(tbl && val);
+ *val = NULL; // so on failure we can just return;
+ if (tbl->weight == 0)
+ return KNOT_ENOENT;
+ { // Intentionally un-indented; until end of function, to bound cleanup attr.
+ // First find a key with longest-matching prefix
+ __attribute__((cleanup(ns_cleanup)))
+ nstack_t ns_local;
+ ns_init(&ns_local, tbl);
+ nstack_t *ns = &ns_local;
+ branch_t bp;
+ int un_leaf; // first unmatched character in the leaf
+ ERR_RETURN(ns_find_branch(ns, key, len, &bp, &un_leaf));
+ int un_key = bp.index < len ? (unsigned char)key[bp.index] : -256;
+ node_t *t = ns->stack[ns->len - 1];
+ if (bp.flags == 0) { // found exact match
+ *val = &t->leaf.val;
+ return KNOT_EOK;
+ }
+ // Get t: the last node on matching path
+ if (isbranch(t) && t->branch.index == bp.index && t->branch.flags == bp.flags) {
+ // t is OK
+ } else {
+ // the top of the stack was the first unmatched node -> step up
+ if (ns->len == 1) {
+ // root was unmatched already
+ if (un_key < un_leaf)
+ return KNOT_ENOENT;
+ ERR_RETURN(ns_last_leaf(ns));
+ goto success;
+ }
+ --ns->len;
+ t = ns->stack[ns->len - 1];
+ }
+ // Now we re-do the first "non-matching" step in the trie
+ // but try the previous child if key was less (it may not exist)
+ bitmap_t b = twigbit(t, key, len);
+ int i = hastwig(t, b)
+ ? twigoff(t, b) - (un_key < un_leaf)
+ : twigoff(t, b) - 1 /*twigoff returns successor when !hastwig*/;
+ if (i >= 0) {
+ ERR_RETURN(ns_longer(ns));
+ ns->stack[ns->len++] = twig(t, i);
+ ERR_RETURN(ns_last_leaf(ns));
+ } else {
+ ERR_RETURN(ns_prev_leaf(ns));
+ }
+success:
+ assert(!isbranch(ns->stack[ns->len - 1]));
+ *val = &ns->stack[ns->len - 1]->leaf.val;
+ return 1;
+ }
+}
+
+/*! \brief Initialize a new leaf, copying the key, and returning failure code. */
+static int mk_leaf(node_t *leaf, const char *key, uint32_t len, knot_mm_t *mm)
+{
+ tkey_t *k = mm_alloc(mm, sizeof(tkey_t) + len);
+ #if FLAGS_HACK
+ assert(((uintptr_t)k) % 4 == 0); // we need an aligned pointer
+ #endif
+ if (unlikely(!k))
+ return KNOT_ENOMEM;
+ k->len = len;
+ memcpy(k->chars, key, len);
+ leaf->leaf = (leaf_t){
+ #if !FLAGS_HACK
+ .flags = 0,
+ #endif
+ .val = NULL,
+ .key = k
+ };
+ return KNOT_EOK;
+}
+
+trie_val_t* trie_get_ins(trie_t *tbl, const char *key, uint32_t len)
+{
+ assert(tbl);
+ // First leaf in an empty tbl?
+ if (unlikely(!tbl->weight)) {
+ if (unlikely(mk_leaf(&tbl->root, key, len, &tbl->mm)))
+ return NULL;
+ ++tbl->weight;
+ return &tbl->root.leaf.val;
+ }
+ { // Intentionally un-indented; until end of function, to bound cleanup attr.
+ // Find the branching-point
+ __attribute__((cleanup(ns_cleanup)))
+ nstack_t ns_local;
+ ns_init(&ns_local, tbl);
+ nstack_t *ns = &ns_local;
+ branch_t bp; // branch-point: index and flags signifying the longest common prefix
+ int k2; // the first unmatched character in the leaf
+ if (unlikely(ns_find_branch(ns, key, len, &bp, &k2)))
+ return NULL;
+ node_t *t = ns->stack[ns->len - 1];
+ if (bp.flags == 0) // the same key was already present
+ return &t->leaf.val;
+ node_t leaf;
+ if (unlikely(mk_leaf(&leaf, key, len, &tbl->mm)))
+ return NULL;
+
+ if (isbranch(t) && bp.index == t->branch.index && bp.flags == t->branch.flags) {
+ // The node t needs a new leaf child.
+ bitmap_t b1 = twigbit(t, key, len);
+ assert(!hastwig(t, b1));
+ uint s, m; TWIGOFFMAX(s, m, t, b1); // new child position and original child count
+ node_t *twigs = mm_realloc(&tbl->mm, t->branch.twigs,
+ sizeof(node_t) * (m + 1), sizeof(node_t) * m);
+ if (unlikely(!twigs))
+ goto err_leaf;
+ memmove(twigs + s + 1, twigs + s, sizeof(node_t) * (m - s));
+ twigs[s] = leaf;
+ t->branch.twigs = twigs;
+ t->branch.bitmap |= b1;
+ ++tbl->weight;
+ return &twigs[s].leaf.val;
+ } else {
+ // We need to insert a new binary branch with leaf at *t.
+ // Note: it works the same for the case where we insert above root t.
+ #ifndef NDEBUG
+ if (ns->len > 1) {
+ node_t *pt = ns->stack[ns->len - 2];
+ assert(hastwig(pt, twigbit(pt, key, len)));
+ }
+ #endif
+ node_t *twigs = mm_alloc(&tbl->mm, sizeof(node_t) * 2);
+ if (unlikely(!twigs))
+ goto err_leaf;
+ node_t t2 = *t; // Save before overwriting t.
+ t->branch.flags = bp.flags;
+ t->branch.index = bp.index;
+ t->branch.twigs = twigs;
+ bitmap_t b1 = twigbit(t, key, len);
+ bitmap_t b2 = unlikely(k2 == -256) ? (1 << 0) : nibbit(k2, bp.flags);
+ t->branch.bitmap = b1 | b2;
+ *twig(t, twigoff(t, b1)) = leaf;
+ *twig(t, twigoff(t, b2)) = t2;
+ ++tbl->weight;
+ return &twig(t, twigoff(t, b1))->leaf.val;
+ };
+err_leaf:
+ mm_free(&tbl->mm, leaf.leaf.key);
+ return NULL;
+ }
+}
+
+/*! \brief Apply a function to every trie_val_t*, in order; a recursive solution. */
+static int apply_trie(node_t *t, int (*f)(trie_val_t *, void *), void *d)
+{
+ assert(t);
+ if (!isbranch(t))
+ return f(&t->leaf.val, d);
+ int child_count = bitmap_weight(t->branch.bitmap);
+ for (int i = 0; i < child_count; ++i)
+ ERR_RETURN(apply_trie(twig(t, i), f, d));
+ return KNOT_EOK;
+}
+
+int trie_apply(trie_t *tbl, int (*f)(trie_val_t *, void *), void *d)
+{
+ assert(tbl && f);
+ if (!tbl->weight)
+ return KNOT_EOK;
+ return apply_trie(&tbl->root, f, d);
+}
+
+/* These are all thin wrappers around static Tns* functions. */
+trie_it_t* trie_it_begin(trie_t *tbl)
+{
+ assert(tbl);
+ trie_it_t *it = malloc(sizeof(nstack_t));
+ if (!it)
+ return NULL;
+ ns_init(it, tbl);
+ if (it->len == 0) // empty tbl
+ return it;
+ if (ns_first_leaf(it)) {
+ ns_cleanup(it);
+ free(it);
+ return NULL;
+ }
+ return it;
+}
+
+void trie_it_next(trie_it_t *it)
+{
+ assert(it && it->len);
+ if (ns_next_leaf(it) != KNOT_EOK)
+ it->len = 0;
+}
+
+bool trie_it_finished(trie_it_t *it)
+{
+ assert(it);
+ return it->len == 0;
+}
+
+void trie_it_free(trie_it_t *it)
+{
+ if (!it)
+ return;
+ ns_cleanup(it);
+ free(it);
+}
+
+const char* trie_it_key(trie_it_t *it, size_t *len)
+{
+ assert(it && it->len);
+ node_t *t = it->stack[it->len - 1];
+ assert(!isbranch(t));
+ tkey_t *key = t->leaf.key;
+ if (len)
+ *len = key->len;
+ return key->chars;
+}
+
+trie_val_t* trie_it_val(trie_it_t *it)
+{
+ assert(it && it->len);
+ node_t *t = it->stack[it->len - 1];
+ assert(!isbranch(t));
+ return &t->leaf.val;
+}
diff --git a/lib/generic/trie.h b/lib/generic/trie.h
new file mode 100644
index 0000000..dd9d3eb
--- /dev/null
+++ b/lib/generic/trie.h
@@ -0,0 +1,139 @@
+/* Copyright (C) 2017-2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <libknot/mm_ctx.h>
+#include "lib/defines.h"
+
+/*!
+ * \brief Native API of QP-tries:
+ *
+ * - keys are char strings, not necessarily zero-terminated,
+ * the structure copies the contents of the passed keys
+ * - values are void* pointers, typically you get an ephemeral pointer to it
+ * - key lengths are limited by 2^32-1 ATM
+ *
+ * XXX EDITORS: trie.{h,c} are synced from
+ * https://gitlab.nic.cz/knot/knot-dns/tree/68352fc969/src/contrib/qp-trie
+ * only with tiny adjustments, mostly include lines and KR_EXPORT.
+ */
+
+/*! \brief Element value. */
+typedef void* trie_val_t;
+
+/*! \brief Opaque structure holding a QP-trie. */
+typedef struct trie trie_t;
+
+/*! \brief Opaque type for holding a QP-trie iterator. */
+typedef struct trie_it trie_it_t;
+
+/*! \brief Create a trie instance. Pass NULL to use malloc+free. */
+KR_EXPORT
+trie_t* trie_create(knot_mm_t *mm);
+
+/*! \brief Free a trie instance. */
+KR_EXPORT
+void trie_free(trie_t *tbl);
+
+/*! \brief Clear a trie instance (make it empty). */
+KR_EXPORT
+void trie_clear(trie_t *tbl);
+
+/*! \brief Return the number of keys in the trie. */
+KR_EXPORT
+size_t trie_weight(const trie_t *tbl);
+
+/*! \brief Search the trie, returning NULL on failure. */
+KR_EXPORT
+trie_val_t* trie_get_try(trie_t *tbl, const char *key, uint32_t len);
+
+/*!
+ * \brief Return pointer to the minimum. Optionally with key and its length. */
+KR_EXPORT
+trie_val_t* trie_get_first(trie_t *tbl, char **key, uint32_t *len);
+
+/*! \brief Search the trie, inserting NULL trie_val_t on failure. */
+KR_EXPORT
+trie_val_t* trie_get_ins(trie_t *tbl, const char *key, uint32_t len);
+
+/*!
+ * \brief Search for less-or-equal element.
+ *
+ * \param tbl Trie.
+ * \param key Searched key.
+ * \param len Key length.
+ * \param val Must be valid; it will be set to NULL if not found or errored.
+ * \return KNOT_EOK for exact match, 1 for previous, KNOT_ENOENT for not-found,
+ * or KNOT_E*.
+ */
+KR_EXPORT
+int trie_get_leq(trie_t *tbl, const char *key, uint32_t len, trie_val_t **val);
+
+/*!
+ * \brief Apply a function to every trie_val_t, in order.
+ *
+ * \param d Parameter passed as the second argument to f().
+ * \return First nonzero from f() or zero (i.e. KNOT_EOK).
+ */
+KR_EXPORT
+int trie_apply(trie_t *tbl, int (*f)(trie_val_t *, void *), void *d);
+
+/*!
+ * \brief Remove an item, returning KNOT_EOK if succeeded or KNOT_ENOENT if not found.
+ *
+ * If val!=NULL and deletion succeeded, the deleted value is set.
+ */
+KR_EXPORT
+int trie_del(trie_t *tbl, const char *key, uint32_t len, trie_val_t *val);
+
+/*!
+ * \brief Remove the first item, returning KNOT_EOK on success.
+ *
+ * You may optionally get the key and/or value.
+ * The key is copied, so you need to pass sufficient len,
+ * otherwise kr_error(ENOSPC) is returned.
+ */
+KR_EXPORT
+int trie_del_first(trie_t *tbl, char *key, uint32_t *len, trie_val_t *val);
+
+/*! \brief Create a new iterator pointing to the first element (if any). */
+KR_EXPORT
+trie_it_t* trie_it_begin(trie_t *tbl);
+
+/*!
+ * \brief Advance the iterator to the next element.
+ *
+ * Iteration is in ascending lexicographical order.
+ * In particular, the empty string would be considered as the very first.
+ *
+ * \note You may not use this function if the trie's key-set has been modified
+ * during the lifetime of the iterator (modifying values only is OK).
+ */
+KR_EXPORT
+void trie_it_next(trie_it_t *it);
+
+/*! \brief Test if the iterator has gone past the last element. */
+KR_EXPORT
+bool trie_it_finished(trie_it_t *it);
+
+/*! \brief Free any resources of the iterator. It's OK to call it on NULL. */
+KR_EXPORT
+void trie_it_free(trie_it_t *it);
+
+/*!
+ * \brief Return pointer to the key of the current element.
+ *
+ * \note The optional len is uint32_t internally but size_t is better for our usage,
+ * as it is without an additional type conversion.
+ */
+KR_EXPORT
+const char* trie_it_key(trie_it_t *it, size_t *len);
+
+/*! \brief Return pointer to the value of the current element (writable). */
+KR_EXPORT
+trie_val_t* trie_it_val(trie_it_t *it);
diff --git a/lib/generic/trie.spdx b/lib/generic/trie.spdx
new file mode 100644
index 0000000..e8d52f2
--- /dev/null
+++ b/lib/generic/trie.spdx
@@ -0,0 +1,10 @@
+SPDXVersion: SPDX-2.1
+DataLicense: CC0-1.0
+SPDXID: SPDXRef-DOCUMENT
+DocumentName: knotdns-trie
+DocumentNamespace: http://spdx.org/spdxdocs/spdx-v2.1-f99c0e11-6afb-46ce-af96-0955a83957bb
+
+PackageName: knotdns-trie
+PackageDownloadLocation: git+https://gitlab.nic.cz/knot/knot-dns.git@68352fc969bc04aa4aa8203e113ce747d887f410#src/contrib/qp-trie/trie.c
+PackageOriginator: Organization: Knot DNS contributors
+PackageLicenseDeclared: GPL-3.0-or-later
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-07 21:21:55 +0000