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skiplist/examples/slm.c

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// OPTIONS to set before including sl.h
// ---------------------------------------------------------------------------
#define DEBUG
#define SKIPLIST_DIAGNOSTIC
/* Setting SKIPLIST_MAX_HEIGHT will do two things:
* 1) limit our max height across all instances of this data structure.
* 2) remove a heap allocation on frequently used paths, insert/remove/etc.
* so, use it when you need it.
*/
#define SKIPLIST_MAX_HEIGHT 12
// Include our monolithic ADT, the Skiplist!
// ---------------------------------------------------------------------------
#include "../include/sl.h"
// Local demo application OPTIONS:
// ---------------------------------------------------------------------------
#define VALIDATE
#define SNAPSHOTS
#define DOT
#define TEST_ARRAY_SIZE 10
// ---------------------------------------------------------------------------
#ifdef VALIDATE
#define CHECK __skip_integrity_check_sample(list, 0)
#else
#define CHECK ((void)0)
#endif
/*
* SKIPLIST EXAMPLE:
*
* This example creates a "sample" Skiplist where keys are integers, values are
* strings allocated on the heap.
*
* 'sample' - meaning: EXample
*/
/*
* To start, you must create a type node that will contain the
* fields you'd like to maintain in your Skiplist. In this case
* we map int -> char [] on the heap, but what you put here is up
* to you. You don't even need a "key", just a way to compare one
* node against another, logic you'll provide in SKIP_DECL as a
* block below.
*/
struct sample_node {
int key;
char *value;
SKIPLIST_ENTRY(sample) entries;
};
/*
* Generate all the access functions for our type of Skiplist.
*/
SKIPLIST_DECL(
sample, api_, entries,
/* compare entries: list, a, b, aux */
{
(void)list;
(void)aux;
if (a->key < b->key)
return -1;
if (a->key > b->key)
return 1;
return 0;
},
/* free entry: node */
{ free(node->value); },
/* update entry: rc, src, dest */
{
char *new = calloc(strlen(node->value) + 1, sizeof(char));
if (new == NULL) {
rc = ENOMEM;
} else {
strncpy(new, node->value, strlen(node->value));
free(node->value);
node->value = new;
}
},
/* archive an entry: rc, src, dest */
{
dest->key = src->key;
char *nv = calloc(strlen(src->value) + 1, sizeof(char));
if (nv == NULL)
rc = ENOMEM;
else {
strncpy(nv, src->value, strlen(src->value));
dest->value = nv;
}
},
/* size in bytes of the content stored in an entry: bytes */
{ bytes = strlen(node->value) + 1; })
/*
* Skiplists are ordered, we need a way to compare entries.
* Let's create a function with four arguments:
* - a reference to the Skiplist, `slist`
* - the two nodes to compare, `a` and `b`
* - and `aux`, which you can use to pass into this function
* any additional information required to compare objects.
* `aux` is passed from the value in the Skiplist, you can
* modify that value at any time to suit your needs.
*
* Your function should result in a return statement:
* a < b : return -1
* a == b : return 0
* a > b : return 1
*
* This result provides the ordering within the Skiplist. Sometimes
* your function will not be used when comparing nodes. This will
* happen when `a` or `b` are references to the head or tail of the
* list or when `a == b`. In those cases the comparison function
* returns before using the code in your block, don't panic. :)
int
__sample_key_compare(sample_t *list, sample_node_t *a, sample_node_t *b, void *aux)
{
(void)list;
(void)aux;
if (a->key < b->key)
return -1;
if (a->key > b->key)
return 1;
return 0;
}
*/
/*
* Optional: Getters and Setters
* - get, put, dup(put), del, etc. functions
*
* It can be useful to have simple get/put-style API, but to
* do that you'll have to supply some blocks of code used to
* extract data from within your nodes.
*/
SKIPLIST_DECL_ACCESS(
sample, api_, key, int, value, char *,
/* query blk */ { query.key = key; },
/* return blk */ { return node->value; })
/*
* Optional: Snapshots
*
* TODO
*/
SKIPLIST_DECL_SNAPSHOTS(sample, api_, entries)
/*
* Optional: Archive to/from bytes
*
* TODO
*/
SKIPLIST_DECL_ARCHIVE(sample, api_, entries)
/*
* Optional: As Hashtable
*
* Turn your Skiplist into a hash table. TODO
*/
// SKIPLIST_DECL_HASHTABLE(sample, api_, entries, snaps)
/*
* Optional: Check Skiplists at runtime
*
* Create a functions that validate the integrity of a Skiplist.
*/
SKIPLIST_DECL_VALIDATE(sample, api_, entries)
/* Optional: Visualize your Skiplist using DOT/Graphviz in PDF
*
* Create the functions used to annotate a visualization of a Skiplist.
*/
SKIPLIST_DECL_DOT(sample, api_, entries)
void
sprintf_sample_node(sample_node_t *node, char *buf)
{
sprintf(buf, "%d:%s", node->key, node->value);
}
// Function for this demo application.
// ---------------------------------------------------------------------------
static char *
to_lower(char *str)
{
char *p = str;
for (; *p; ++p)
*p = (char)(*p >= 'A' && *p <= 'Z' ? *p | 0x60 : *p);
return str;
}
static char *
to_upper(char *str)
{
char *p = str;
for (; *p; ++p)
*p = (char)(*p >= 'a' && *p <= 'z' ? *p & ~0x20 : *p);
return str;
}
static char *
int_to_roman_numeral(int num)
{
int del[] = { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 }; // Key value in Roman counting
char *sym[] = { "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I" }; // Symbols for key values
// The maximum length of the Roman numeral representation for the maximum signed 64-bit integer would be approximately 19 * 3 = 57 characters, assuming
// every digit is represented by its Roman numeral equivalent up to 3 repetitions. Therefore, 64 should be more than enough.
char *res = (char *)calloc(4096, sizeof(char));
int i = 0;
if (num < 0) {
res[0] = '-';
i++;
num = -num;
}
if (num == 0) {
res[0] = '0';
return res;
}
while (num) { // while input number is not zero
while (num / del[i]) { // while a number contains the largest key value possible
strcat(res, sym[i]); // append the symbol for this key value to res string
num -= del[i]; // subtract the key value from number
}
i++; // proceed to the next key value
}
return res;
}
void
shuffle(int *array, size_t n)
{
if (n > 1) {
size_t i;
for (i = n - 1; i > 0; i--) {
size_t j = (unsigned int)(rand() % (i + 1)); /* NOLINT(*-msc50-cpp) */
int t = array[j];
array[j] = array[i];
array[i] = t;
}
}
}
// ---------------------------------------------------------------------------
int
main()
{
int rc;
#ifdef SNAPSHOTS
size_t snap_i = 0;
uint64_t snap_ids[2048];
#endif
#ifdef DOT
size_t gen = 0;
FILE *of = fopen("/tmp/slm.dot", "w");
if (!of) {
perror("Failed to open file /tmp/slm.dot");
return 1;
}
#endif
/* Allocate and initialize a Skiplist. */
sample_t *list = (sample_t *)malloc(sizeof(sample_t));
if (list == NULL)
return ENOMEM;
rc = api_skip_init_sample(list, 12); // TODO -12
if (rc)
return rc;
api_skip_snapshots_init_sample(list);
#ifdef DOT
api_skip_dot_sample(of, list, gen++, "init", sprintf_sample_node);
#endif
if (api_skip_get_sample(list, 0) != NULL)
perror("found a non-existent item!");
api_skip_del_sample(list, 0);
CHECK;
#ifdef SNAPSHOTS
/* Test creating a snapshot of an empty Skiplist */
snap_ids[snap_i++] = api_skip_snapshot_sample(list);
#endif
/* Insert 7 key/value pairs into the list. */
int i, j;
char *numeral;
#ifdef DOT
char msg[1024];
memset(msg, 0, 1024);
#endif
int amt = TEST_ARRAY_SIZE, asz = (amt * 2) + 1;
int array[(TEST_ARRAY_SIZE * 2) + 1];
for (j = 0, i = -amt; i <= amt; i++, j++)
array[j] = i;
shuffle(array, asz);
for (i = 0; i < asz; i++) {
numeral = int_to_roman_numeral(array[i]);
rc = api_skip_put_sample(list, array[i], to_lower(numeral));
CHECK;
#ifdef SNAPSHOTS
if (i > TEST_ARRAY_SIZE + 1) {
snap_ids[snap_i++] = api_skip_snapshot_sample(list);
CHECK;
}
#endif
#ifdef DOT
sprintf(msg, "put key: %d value: %s", i, numeral);
api_skip_dot_sample(of, list, gen++, msg, sprintf_sample_node);
CHECK;
#endif
char *v = api_skip_get_sample(list, array[i]);
CHECK;
api_skip_set_sample(list, array[i], to_upper(v));
CHECK;
}
numeral = int_to_roman_numeral(-1);
api_skip_dup_sample(list, -1, numeral);
CHECK;
#ifdef DOT
sprintf(msg, "put dup key: %d value: %s", i, numeral);
api_skip_dot_sample(of, list, gen++, msg, sprintf_sample_node);
CHECK;
#endif
numeral = int_to_roman_numeral(1);
api_skip_dup_sample(list, 1, numeral);
CHECK;
#ifdef DOT
sprintf(msg, "put dup key: %d value: %s", i, numeral);
api_skip_dot_sample(of, list, gen++, msg, sprintf_sample_node);
CHECK;
#endif
api_skip_del_sample(list, 0);
CHECK;
if (api_skip_get_sample(list, 0) != NULL)
perror("found a deleted item!");
api_skip_del_sample(list, 0);
CHECK;
if (api_skip_get_sample(list, 0) != NULL)
perror("found a deleted item!");
int key = TEST_ARRAY_SIZE + 1;
api_skip_del_sample(list, key);
CHECK;
key = -(TEST_ARRAY_SIZE)-1;
numeral = int_to_roman_numeral(key);
api_skip_del_sample(list, key);
CHECK;
#ifdef DOT
sprintf(msg, "deleted key: %d, value: %s", 0, numeral);
api_skip_dot_sample(of, list, gen++, msg, sprintf_sample_node);
CHECK;
#endif
#ifdef SNAPSHOTS
// TODO api_skip_restore_snapshot_sample(list, snap_ids[snap_i - 1]);
// TODO api_skip_release_snapshots_sample(list);
#endif
assert(strcmp(api_skip_pos_sample(list, SKIP_GTE, -(TEST_ARRAY_SIZE)-1)->value, int_to_roman_numeral(-(TEST_ARRAY_SIZE))) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_GTE, -2)->value, int_to_roman_numeral(-2)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_GTE, 0)->value, int_to_roman_numeral(1)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_GTE, 2)->value, int_to_roman_numeral(2)) == 0);
assert(api_skip_pos_sample(list, SKIP_GTE, (TEST_ARRAY_SIZE + 1)) == NULL);
assert(strcmp(api_skip_pos_sample(list, SKIP_GT, -(TEST_ARRAY_SIZE)-1)->value, int_to_roman_numeral(-(TEST_ARRAY_SIZE))) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_GT, -2)->value, int_to_roman_numeral(-1)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_GT, 0)->value, int_to_roman_numeral(1)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_GT, 1)->value, int_to_roman_numeral(2)) == 0);
assert(api_skip_pos_sample(list, SKIP_GT, TEST_ARRAY_SIZE) == NULL);
assert(api_skip_pos_sample(list, SKIP_LT, -(TEST_ARRAY_SIZE)) == NULL);
assert(strcmp(api_skip_pos_sample(list, SKIP_LT, -1)->value, int_to_roman_numeral(-2)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_LT, 0)->value, int_to_roman_numeral(-1)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_LT, 2)->value, int_to_roman_numeral(1)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_LT, (TEST_ARRAY_SIZE + 1))->value, int_to_roman_numeral(TEST_ARRAY_SIZE)) == 0);
assert(api_skip_pos_sample(list, SKIP_LTE, -(TEST_ARRAY_SIZE)-1) == NULL);
assert(strcmp(api_skip_pos_sample(list, SKIP_LTE, -2)->value, int_to_roman_numeral(-2)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_LTE, 0)->value, int_to_roman_numeral(-1)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_LTE, 2)->value, int_to_roman_numeral(2)) == 0);
assert(strcmp(api_skip_pos_sample(list, SKIP_LTE, (TEST_ARRAY_SIZE + 1))->value, int_to_roman_numeral(TEST_ARRAY_SIZE)) == 0);
api_skip_free_sample(list);
#ifdef DOT
api_skip_dot_end_sample(of, gen);
fclose(of);
#endif
return rc;
}
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