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C Datenstrukturen und Algorithmen

Eine Bibliothek generischer aufdringlicher Datenstrukturen und Algorithmen in ANSI C

• Hintergrund
• Beispiele
• Installation
• Auslauftests
• Beitragen

Hintergrund

Dieses Repository ist ein laufendes Projekt bei der Implementierung generischer intrusionsübergreifender Datenstrukturen und Algorithmen in ANSI C. Ich finde, ich verwende häufig dieselben Konstrukte, die eine Menge Boilerplate -Code erfordern. Daher habe ich dieses Repository gemacht, um diese Konstrukte zu organisieren und eine einfache Integration dieser Konstrukte in vorhandene Projekte zu ermöglichen.

Meine Designphilosophie mit diesem Repository besteht darin, eine minimalistische API für jede Datenstruktur anzubieten, die alle Tools enthält, die für die einfache Erstellung von komplexeren/Nischenkonstrukten erforderlich sind. Die Portabilität hat oberste Priorität, daher wird nur ANSI C verwendet, und kein Header/Quellpaar stützt sich auf ein anderes Header/Quellpaar. Um in eingebetteten Systemen zu fördern, werden iterative Algorithmen ausschließlich über rekursive Algorithmen verwendet, und jede Datenstruktur ist aufdringlich (für bessere Speicherlokalität).

Verwenden Sie diese Datenstrukturen und Algorithmen auf Ihre eigene Weise. Der Code ist unter der ISC -Lizenz lizenziert (eine vereinfachte Version der BSD -Lizenz, die funktional identisch ist); Somit kann es in einem Projekt zu Recht wiederverwendet werden, ob proprietär oder open Source.

Beispiele

Jeder Header ist stark dokumentiert und sollte hoffentlich alle Fragen zur Funktionalität beantworten. Eine eingehende Erläuterung, wie jede Datenstruktur funktioniert, befindet sich oben in der Header-Datei.

Liste

 // Define your struct somewhere.
struct Object {
    int some_value ;
    ...

    // Don't forget to embed the ListNode!
    ListNode node ;
};

...

// Create some Object variables.
struct Object obj1 , obj2 ;
obj1 . some_value = 1 ;
obj2 . some_value = 2 ;

// Create your List.
List my_list ;
list_init ( & my_list );

// Populate your List. Notice how the API abstracts itself and only cares about the ListNode.
list_insert_back ( & my_list , & obj1 . node );
list_insert_back ( & my_list , & obj2 . node );

// Let's see what is stored in the List:
int i = 1 ;
ListNode * n ;
list_for_each ( n , & my_list ) {
    if ( i == 1 ) {
        assert ( n == & obj1 . node );
    } else if ( i == 2 ){
        assert ( n == & obj2 . node );
    }

    ++ i ;
}

...

// Let's get the ListNode at the front of the List.
ListNode * front_node_ptr = list_front ( & my_list );

// Getting the "node" member from an Object variable is easy: ("obj1.node"),
// but how do you get the Object variable when you only have the "node" member?
// Solution: the macro "list_entry":
struct Object * obj_ptr = list_entry ( front_node_ptr , struct Object , node );
assert ( obj_ptr == & obj1 );

Rbtree

 // Define your struct somewhere.
struct Object {
    int key ;
    ...

    // Don't forget to embed the RBTreeNode!
    RBTreeNode node ;
};

...

// You must define a compare function which compares a key with the key of a RBTreeNode.
int compare ( const void * some_key , const RBTreeNode * some_node ) {
    return * ( const int * ) some_key - rbtree_entry ( some_node , struct Object , node ) -> key ;
}

// You can OPTIONALLY define a collide function which handles key collisions. When a key
// collision happens, no matter what, the old RBTreeNode will be replaced by the new
// RBTreeNode. If this function is defined, then it will be called after the old
// RBTreeNode is replaced in the RBTree. This function is great if you need to free up
// resources in the Object variable pertaining to the discarded RBTreeNode. This function
// is also great for enabling multi-key functionality in the RBTree.
void collide ( const RBTreeNode * old_node , const RBTreeNode * new_node , void * auxiliary_data ) {
    // When a RBTree is created, we can give it auxiliary data to hold onto. This data is then
    // passed to this function for usage. This data, for example, could be a memory pool struct
    // that is needed to free up the resources used by the Object variable pertaining to the
    // old_node parameter.

    ...
}

...

// Create some Object variables.
struct Object obj1 , obj2 ;
obj1 . key = 1 ;
obj2 . key = 2 ;

// Create you RBTree. In this case we don't have any auxiliary data that needs to be used
// in the collide function, so we just pass NULL. As previously mentioned, the collide
// function itself is optional. If you don't need to do any special resource management,
// just pass "NULL" in place of "collide" in the initialize function.
RBTree my_rbtree ;
rbtree_init ( & my_rbtree , compare , collide , NULL );

// Populate your RBTree. Notice how the API abstracts itself and only cares about the
// RBTreeNode and its key. Because red black trees are always ordered in some way, order
// of insertion will never affect the inorderness of the tree.
rbtree_insert ( & my_rbtree , & obj2 . key , & obj2 . node );
rbtree_insert ( & my_rbtree , & obj1 . key , & obj1 . node );

// Because of the way our compare function is designed, the RBTree stores its RBTreeNodes
// inorder from smallest key to greatest key. Let's see what is stored in the RBTree:
int i = 1 ;
RBTreeNode * n ;
rbtree_for_each ( n , & my_rbtree ) {
    if ( i == 1 ) {
        assert ( n == & obj1 . node );
    } else if ( i == 2 ) {
        assert ( n == & obj2 . node );
    }

    ++ i ;
}

...

// Let's get the RBTreeNode with the greatest key.
RBTreeNode * greatest_node_ptr = rbtree_last ( & my_rbtree );

// Getting the "node" member from an Object variable is easy: ("obj1.node"),
// but how do you get the Object variable when you only have the "node" member?
// Solution: the macro "rbtree_entry":
struct Object * obj_ptr = rbtree_entry ( greatest_node_ptr , struct Object , node );
assert ( obj_ptr == & obj2 );

Hashtable

 // Define your struct somewhere.
struct Object {
    int key ;
    ...

    // Don't forget to embed the HashTableNode!
    HashTableNode node ;
};

...

// You must define a hash function which takes in a key and returns its hashcode. In this
// case we aren't going to do anything fancy since this is just an example.
size_t hash ( const void * key ) {
    return * ( const int * ) key ;
}

// You must define an equal function which determines if a key is equal to the key of a HashTableNode.
int equal ( const void * some_key , const HashTableNode * some_node ) {
    return * ( const int * ) some_key == hashtable_entry ( some_node , struct Object , node ) -> key ;
}

// You can OPTIONALLY define a collide function which handles key collisions. When a key
// collision happens, no matter what, the old HashTableNode will be replaced by the new
// HashTableNode. If this function is defined, then it will be called after the old
// HashTableNode is replaced in the HashTable. This function is great if you need to free up
// resources in the Object variable pertaining to the discarded HashTableNode. This function
// is also great for enabling multi-key functionality in the HashTable.
void collide ( const HashTableNode * old_node , const HashTableNode * new_node , void * auxiliary_data ) {
    // When a HashTable is created, we can give it auxiliary data to hold onto. This data is then
    // passed to this function for usage. This data, for example, could be a memory pool struct
    // that is needed to free up the resources used by the Object variable pertaining to the
    // old_node parameter.

    ...
}

...

// Create some Object variables.
struct Object obj1 , obj2 ;
obj1 . key = 1 ;
obj2 . key = 2 ;

// You must create a bucket array which is an array of pointers to HashTableNodes. This
// array is used by the HashTable for the duration of its lifetime. In this case we will
// have 50 buckets in the bucket array.
HashTableNode * bucket_array [ 50 ];

// Create you HashTable. In this case we don't have any auxiliary data that needs to be used
// in the collide function, so we just pass NULL. As previously mentioned, the collide
// function itself is optional. If you don't need to do any special resource management,
// just pass "NULL" in place of "collide" in the initialize function.
HashTable my_hashtable ;
hashtable_init ( & my_hashtable , bucket_array , 50 , hash , equal , collide , NULL );

// Populate your HashTable. Notice how the API abstracts itself and only cares about the
// HashTableNode and its key.
hashtable_insert ( & my_hashtable , & obj1 . key , & obj1 . node );
hashtable_insert ( & my_hashtable , & obj2 . key , & obj2 . node );

// HashTable provides no guarantee on the ordering of HashTableNodes in the bucket array.
// Let's see what is stored in the HashTable:
int sum_of_keys = 0 , bucket_index ;
HashTableNode * n ;
hashtable_for_each ( n , bucket_index , & my_hashtable ) {
    sum_of_keys += hashtable_entry ( n , struct Object , node ) -> key ;
}
assert ( sum_of_keys == 3 );

...

// Let's get the HashTableNode with the key that equals 1.
int key = 1 ;
HashTableNode * node_ptr = hashtable_lookup_key ( & my_hashtable , & key );

// Getting the "node" member from an Object variable is easy: ("obj1.node"),
// but how do you get the Object variable when you only have the "node" member?
// Solution: the macro "hashtable_entry":
struct Object * obj_ptr = hashtable_entry ( node_ptr , struct Object , node );
assert ( obj_ptr == & obj1 );

Stapel

 // Define your struct somewhere.
struct Object {
    int some_value ;
    ...

    // Don't forget to embed the StackNode!
    StackNode node ;
};

...

// Create some Object variables.
struct Object obj1 , obj2 ;
obj1 . some_value = 1 ;
obj2 . some_value = 2 ;

// Create your Stack.
Stack my_stack ;
stack_init ( & my_stack );

// Populate your Stack. Notice how the API abstracts itself and only cares about the StackNode.
stack_push ( & my_stack , & obj1 . node );
stack_push ( & my_stack , & obj2 . node );

// Let's see what is stored in the Stack:
int i = 1 ;
StackNode * n ;
stack_for_each ( n , & my_stack ) {
    if ( i == 1 ) {
        assert ( n == & obj2 . node );
    } else if ( i == 2 ){
        assert ( n == & obj1 . node );
    }

    ++ i ;
}

...

// Let's get the StackNode at the top of the Stack.
StackNode * top_node_ptr = stack_peek ( & my_stack );

// Getting the "node" member from an Object variable is easy: ("obj1.node"),
// but how do you get the Object variable when you only have the "node" member?
// Solution: the macro "stack_entry":
struct Object * obj_ptr = stack_entry ( top_node_ptr , struct Object , node );
assert ( obj_ptr == & obj2 );

Warteschlange

 // Define your struct somewhere.
struct Object {
    int some_value ;
    ...

    // Don't forget to embed the QueueNode!
    QueueNode node ;
};

...

// Create some Object variables.
struct Object obj1 , obj2 ;
obj1 . some_value = 1 ;
obj2 . some_value = 2 ;

// Create your Queue.
Queue my_queue ;
queue_init ( & my_queue );

// Populate your Queue. Notice how the API abstracts itself and only cares about the QueueNode.
queue_push ( & my_queue , & obj1 . node );
queue_push ( & my_queue , & obj2 . node );

// Let's see what is stored in the Queue:
int i = 1 ;
QueueNode * n ;
queue_for_each ( n , & my_queue ) {
    if ( i == 1 ) {
        assert ( n == & obj1 . node );
    } else if ( i == 2 ){
        assert ( n == & obj2 . node );
    }

    ++ i ;
}

...

// Let's get the QueueNode at the front of the Queue.
QueueNode * front_node_ptr = queue_peek ( & my_queue );

// Getting the "node" member from an Object variable is easy: ("obj1.node"),
// but how do you get the Object variable when you only have the "node" member?
// Solution: the macro "queue_entry":
struct Object * obj_ptr = queue_entry ( front_node_ptr , struct Object , node );
assert ( obj_ptr == & obj1 );

Installation

Diese Bibliothek ist in ANSI C geschrieben, sodass der Code mit nahezu jedem Compiler funktioniert. Jedes Header/Quellpaar ist unabhängig von den anderen. Dies erleichtert die Verwendung einer einzelnen Datenstruktur. Ziehen Sie einfach das Header/Quell -Paar direkt in Ihr Projekt ab und lassen Sie sie zusammen mit Ihren anderen Dateien zusammen mit den Quelldateien zusammenstellen.

Auslauftests

Sie müssen den GNU -Compiler zur Verfügung haben, um die Tests auszuführen. Stellen Sie sicher, dass alle Dateien auch in dieser Bibliothek heruntergeladen werden.

Führen Sie diesen Befehl einfach einmal im Verzeichnis "Tests" aus, um alle Tests auszuführen:

 make

Beispiel:

 cd tests/
make
gcc test_list.c ../src/list.c -o test_list -Wall -Wextra -Werror -pedantic-errors -std=c89
./test_list C89

PASSED: List C89

rm -f test_list
gcc test_list.c ../src/list.c -o test_list -Wall -Wextra -Werror -std=gnu89
./test_list GNU89

PASSED: List GNU89

rm -f test_list
g++ test_list.c ../src/list.c -o test_list -Wall -Wextra -Werror -pedantic-errors -std=c++11
./test_list C++11

PASSED: List C++11

rm -f test_list
g++ test_list.c ../src/list.c -o test_list -Wall -Wextra -Werror -std=gnu++11
./test_list GNU++11

PASSED: List GNU++11

rm -f test_list
gcc test_rbtree.c ../src/rbtree.c -o test_rbtree -Wall -Wextra -Werror -pedantic-errors -std=c89
./test_rbtree C89

PASSED: RBTree C89

rm -f test_rbtree
gcc test_rbtree.c ../src/rbtree.c -o test_rbtree -Wall -Wextra -Werror -std=gnu89
./test_rbtree GNU89

PASSED: RBTree GNU89

etc... (this goes on for a while)

Beitragen

Beiträge sind willkommen!

Wenn Sie eine Funktionsanforderung haben oder einen Fehler gefunden haben, können Sie ein neues Problem eröffnen. Wenn Sie Code beitragen möchten, dokumentieren Sie bitte gründlich und stellen Sie sicher, dass Sie einen Test für jede Funktion/jedes Makro schreiben. Ich werde helfen, den Code abzuschließen und sicherzustellen, dass die verwendeten Konventionen konsistent sind.