The Flat Ordered Map Interface. More...

#include "impl/impl_flat_ordered_map.h"
#include "types.h"

Include dependency graph for flat_ordered_map.h:

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Initialization Interface
Initialize the container with memory, callbacks, and permissions.
#define	ccc_fom_init(mem_ptr, capacity, om_elem_field, key_elem_field, alloc_fn, key_cmp, aux)
	Initializes the map at runtime or compile time.

ccc_result	ccc_fom_copy (ccc_flat_ordered_map dst, ccc_flat_ordered_map const src, ccc_alloc_fn *fn)
	Copy the map at source to destination.

Entry Interface
Obtain and operate on container entries for efficient queries when non-trivial control flow is needed.
#define	ccc_fom_insert_r(flat_ordered_map_ptr, out_handle_ptr)
	Invariantly inserts the key value wrapping key_val_handle.

#define	ccc_fom_try_insert_r(flat_ordered_map_ptr, key_val_handle_ptr)
	Attempts to insert the key value wrapping key_val_handle.

#define	ccc_fom_try_insert_w(flat_ordered_map_ptr, key, lazy_value...)
	lazily insert lazy_value into the map at key if key is absent.

#define	ccc_fom_insert_or_assign_w(flat_ordered_map_ptr, key, lazy_value...)
	Inserts a new key value pair or overwrites the existing entry.

#define	ccc_fom_remove_r(flat_ordered_map_ptr, out_handle_ptr)
	Removes the key value in the map storing the old value, if present, in the struct containing out_handle provided by the user.

#define	ccc_fom_entry_r(flat_ordered_map_ptr, key_ptr)
	Obtains an entry for the provided key in the map for future use.

#define	ccc_fom_and_modify_w(flat_ordered_map_entry_ptr, type_name, closure_over_T...)
	Modify an Occupied entry with a closure over user type T.

#define	ccc_fom_or_insert_w(flat_ordered_map_entry_ptr, lazy_key_value...) ccc_impl_fom_or_insert_w(flat_ordered_map_entry_ptr, lazy_key_value)
	Lazily insert the desired key value into the entry if it is Vacant.

#define	ccc_fom_insert_entry_w(flat_ordered_map_entry_ptr, lazy_key_value...) ccc_impl_fom_insert_entry_w(flat_ordered_map_entry_ptr, lazy_key_value)
	Write the contents of the compound literal lazy_key_value to a node.

#define	ccc_fom_remove_entry_r(flat_ordered_map_entry_ptr)
	Remove the entry from the map if Occupied.

ccc_entry	ccc_fom_insert (ccc_flat_ordered_map fom, ccc_fomap_elem out_handle)
	Invariantly inserts the key value wrapping key_val_handle.

ccc_entry	ccc_fom_try_insert (ccc_flat_ordered_map fom, ccc_fomap_elem key_val_handle)
	Attempts to insert the key value wrapping key_val_handle.

ccc_entry	ccc_fom_insert_or_assign (ccc_flat_ordered_map fom, ccc_fomap_elem key_val_handle)
	Invariantly inserts or overwrites a user struct into the map.

ccc_entry	ccc_fom_remove (ccc_flat_ordered_map fom, ccc_fomap_elem out_handle)
	Removes the key value in the map storing the old value, if present, in the struct containing out_handle provided by the user.

ccc_fomap_entry	ccc_fom_entry (ccc_flat_ordered_map fom, void const key)
	Obtains an entry for the provided key in the map for future use.

ccc_fomap_entry *	ccc_fom_and_modify (ccc_fomap_entry e, ccc_update_fn fn)
	Modifies the provided entry if it is Occupied.

ccc_fomap_entry *	ccc_fom_and_modify_aux (ccc_fomap_entry e, ccc_update_fn fn, void *aux)
	Modifies the provided entry if it is Occupied.

void *	ccc_fom_or_insert (ccc_fomap_entry const e, ccc_fomap_elem elem)
	Inserts the struct with handle elem if the entry is Vacant.

void *	ccc_fom_insert_entry (ccc_fomap_entry const e, ccc_fomap_elem elem)
	Inserts the provided entry invariantly.

ccc_entry	ccc_fom_remove_entry (ccc_fomap_entry *e)
	Remove the entry from the map if Occupied.

void *	ccc_fom_unwrap (ccc_fomap_entry const *e)
	Unwraps the provided entry to obtain a view into the map element.

bool	ccc_fom_occupied (ccc_fomap_entry const *e)
	Returns the Vacant or Occupied status of the entry.

bool	ccc_fom_insert_error (ccc_fomap_entry const *e)
	Provides the status of the entry should an insertion follow.

ccc_entry_status	ccc_fom_entry_status (ccc_fomap_entry const *e)
	Obtain the entry status from a container entry.

Iterator Interface
Obtain and manage iterators over the container.
#define	ccc_fom_equal_range_r(flat_ordered_map_ptr, begin_and_end_key_ptrs...)
	Returns a compound literal reference to the desired range. Amortized O(lg N).

#define	ccc_fom_equal_rrange_r(flat_ordered_map_ptr, rbegin_and_rend_key_ptrs...)
	Returns a compound literal reference to the desired rrange. Amortized O(lg N).

ccc_range	ccc_fom_equal_range (ccc_flat_ordered_map fom, void const begin_key, void const *end_key)
	Return an iterable range of values from [begin_key, end_key). Amortized O(lg N).

ccc_rrange	ccc_fom_equal_rrange (ccc_flat_ordered_map fom, void const rbegin_key, void const *rend_key)
	Return an iterable rrange of values from [rbegin_key, end_key). Amortized O(lg N).

void *	ccc_fom_begin (ccc_flat_ordered_map const *fom)
	Return the start of an inorder traversal of the map. Amortized O(lg N).

void *	ccc_fom_rbegin (ccc_flat_ordered_map const *fom)
	Return the start of a reverse inorder traversal of the map. Amortized O(lg N).

void *	ccc_fom_next (ccc_flat_ordered_map const fom, ccc_fomap_elem const iter_handle)
	Return the next element in an inorder traversal of the map. O(1).

void *	ccc_fom_rnext (ccc_flat_ordered_map const fom, ccc_fomap_elem const iter_handle)
	Return the rnext element in a reverse inorder traversal of the map. O(1).

void *	ccc_fom_end (ccc_flat_ordered_map const *fom)
	Return the end of an inorder traversal of the map. O(1).

void *	ccc_fom_rend (ccc_flat_ordered_map const *fom)
	Return the rend of a reverse inorder traversal of the map. O(1).

Container Types
Types available in the container interface.
typedef struct ccc_fomap_	ccc_flat_ordered_map
	A self-optimizing data structure offering amortized O(lg N) search, insert, and erase.

typedef struct ccc_fomap_elem_	ccc_fomap_elem
	The intrusive element for the user defined type being stored in the map.

typedef union ccc_fomap_entry_	ccc_fomap_entry
	A container specific entry used to implement the Entry Interface.

Membership Interface
Test membership or obtain references to stored user types directly.
bool	ccc_fom_contains (ccc_flat_ordered_map fom, void const key)
	Searches the map for the presence of key.

void *	ccc_fom_get_key_val (ccc_flat_ordered_map fom, void const key)
	Returns a reference into the map at entry key.

Deallocation Interface
Deallocate the container.
ccc_result	ccc_fom_clear (ccc_flat_ordered_map fom, ccc_destructor_fn fn)
	Frees all slots in the map for use without affecting capacity.

ccc_result	ccc_fom_clear_and_free (ccc_flat_ordered_map fom, ccc_destructor_fn fn)
	Frees all slots in the map and frees the underlying buffer.

State Interface
Obtain the container state.
size_t	ccc_fom_size (ccc_flat_ordered_map const *fom)
	Returns the size of the map.

size_t	ccc_fom_capacity (ccc_flat_ordered_map const *fom)
	Returns the capacity of the map.

void *	ccc_fom_data (ccc_flat_ordered_map const *fom)
	Return a reference to the base of backing array. O(1).

bool	ccc_fom_is_empty (ccc_flat_ordered_map const *fom)
	Returns the size status of the map.

bool	ccc_fom_validate (ccc_flat_ordered_map const *fom)
	Validation of invariants for the map.

Detailed Description

The Flat Ordered Map Interface.

A flat ordered map is a contiguously stored map offering storage and retrieval by key. Because the data structure is self-optimizing it is not a suitable map in a realtime environment where strict runtime bounds are needed. Also, searching the map is not a const thread-safe operation as indicated by the function signatures. The map is optimized upon every new search. However, in many cases the self-optimizing structure of the map can be beneficial when considering non-uniform access patterns. In the best case, repeated searches of the same value yield an O(1) access and many other frequently searched values will remain close to the root of the map.

The flat variant of the ordered map promises contiguous storage and random access if needed. Also, all elements in the map track their relationships via indices in the buffer. Therefore, this data structure can be relocated, copied, serialized, or written to disk and all internal data structure references will remain valid. Insertion may invoke an O(N) operation if resizing occurs. Finally, if allocation is prohibited upon initialization and the user intends to store a fixed size N nodes in the map N + 1 capacity is needed for the sentinel node in the buffer.

To shorten names in the interface, define the following preprocessor directive at the top of your file.

#define FLAT_ORDERED_MAP_USING_NAMESPACE_CCC

All types and functions can then be written without the ccc_ prefix.

Macro Definition Documentation

◆ ccc_fom_and_modify_w

#define ccc_fom_and_modify_w	(	flat_ordered_map_entry_ptr,
		type_name,
		closure_over_T...
	)

Value:

    &(ccc_fomap_entry)                                                         \
    {                                                                          \
        ccc_impl_fom_and_modify_w(flat_ordered_map_entry_ptr, type_name,       \
                                  closure_over_T)                              \
    }

Modify an Occupied entry with a closure over user type T.

Parameters

[in]	flat_ordered_map_entry_ptr	a pointer to the obtained entry.
[in]	type_name	the name of the user type stored in the container.
[in]	closure_over_T	the code to be run on the reference to user type T, if Occupied. This may be a semicolon separated list of statements to execute on T or a section of code wrapped in braces {code here} which may be preferred for formatting.

Returns: a compound literal reference to the modified entry if it was occupied or a vacant entry if it was vacant.

Note: T is a reference to the user type stored in the entry guaranteed to be non-NULL if the closure executes.

#define FLAT_ORDERED_MAP_USING_NAMESPACE_CCC
// Increment the key k if found otherwise do nothing.
fom_entry *e = fom_and_modify_w(entry_r(&fom, &k), word, T->cnt++;);
 
// Increment the key k if found otherwise insert a default value.
word *w = fom_or_insert_w(fom_and_modify_w(entry_r(&fom, &k), word,
                                           { T->cnt++; }),
                          (word){.key = k, .cnt = 1});

Note that any code written is only evaluated if the entry is Occupied and the container can deliver the user type T. This means any function calls are lazily evaluated in the closure scope.

◆ ccc_fom_entry_r

#define ccc_fom_entry_r	(	flat_ordered_map_ptr,
		key_ptr
	)

Value:

    &(ccc_fomap_entry)                                                         \
    {                                                                          \
        ccc_fom_entry((flat_ordered_map_ptr), (key_ptr)).impl_                 \
    }

Obtains an entry for the provided key in the map for future use.

Parameters

[in]	flat_ordered_map_ptr	the map to be searched.
[in]	key_ptr	the key used to search the map matching the stored key type.

Returns: a compound literal reference to a specialized entry for use with other functions in the Entry Interface.

Warning: the contents of an entry should not be examined or modified. Use the provided functions, only.

An entry is a search result that provides either an Occupied or Vacant entry in the map. An occupied entry signifies that the search was successful. A Vacant entry means the search was not successful but a handle is gained to where in the map such an element should be inserted.

An entry is rarely useful on its own. It should be passed in a functional style to subsequent calls in the Entry Interface.

◆ ccc_fom_equal_range_r

#define ccc_fom_equal_range_r	(	flat_ordered_map_ptr,
		begin_and_end_key_ptrs...
	)

Value:

    &(ccc_range)                                                               \
    {                                                                          \
        ccc_fom_equal_range(flat_ordered_map_ptr, begin_and_end_key_ptrs)      \
            .impl_                                                             \
    }

Returns a compound literal reference to the desired range. Amortized O(lg N).

Parameters

[in]	flat_ordered_map_ptr	a pointer to the map.
[in]	begin_and_end_key_ptrs	pointers to the begin and end of the range.

Returns: a compound literal reference to the produced range associated with the enclosing scope. This reference is always be valid.

◆ ccc_fom_equal_rrange_r

#define ccc_fom_equal_rrange_r	(	flat_ordered_map_ptr,
		rbegin_and_rend_key_ptrs...
	)

Value:

    &(ccc_rrange)                                                              \
    {                                                                          \
        ccc_fom_equal_rrange(flat_ordered_map_ptr, rbegin_and_rend_key_ptrs)   \
            .impl_                                                             \
    }

Returns a compound literal reference to the desired rrange. Amortized O(lg N).

Parameters

[in]	flat_ordered_map_ptr	a pointer to the map.
[in]	rbegin_and_rend_key_ptrs	pointers to the rbegin and rend of the range.

Returns: a compound literal reference to the produced rrange associated with the enclosing scope. This reference is always valid.

◆ ccc_fom_init

#define ccc_fom_init	(	mem_ptr,
		capacity,
		om_elem_field,
		key_elem_field,
		alloc_fn,
		key_cmp,
		aux
	)

Value:

ccc_impl_fom_init(mem_ptr, capacity, om_elem_field, key_elem_field, \

alloc_fn, key_cmp, aux)

Initializes the map at runtime or compile time.

Parameters

[in]	mem_ptr	a pointer to the contiguous user types or ((T *)NULL).
[in]	capacity	the capacity at mem_ptr or 0 if ((T *)NULL).
[in]	om_elem_field	the name of the intrusive map elem field.
[in]	key_elem_field	the name of the field in user type used as key.
[in]	alloc_fn	the allocation function or NULL if allocation is banned.
[in]	key_cmp	the key comparison function (see types.h).
[in]	aux	a pointer to any auxiliary data for comparison or destruction.

Returns: the struct initialized ordered map for direct assignment (i.e. ccc_flat_ordered_map m = ccc_fom_init(...);).

◆ ccc_fom_insert_entry_w

#define ccc_fom_insert_entry_w	(	flat_ordered_map_entry_ptr,
		lazy_key_value...
	)	ccc_impl_fom_insert_entry_w(flat_ordered_map_entry_ptr, lazy_key_value)

Write the contents of the compound literal lazy_key_value to a node.

Parameters

[in]	flat_ordered_map_entry_ptr	a pointer to the obtained entry.
[in]	lazy_key_value	the compound literal to write to a new slot.

Returns: a reference to the newly inserted or overwritten user type. NULL is returned if allocation failed or is not allowed when required.

◆ ccc_fom_insert_or_assign_w

#define ccc_fom_insert_or_assign_w	(	flat_ordered_map_ptr,
		key,
		lazy_value...
	)

Value:

    &(ccc_entry)                                                               \
    {                                                                          \
        ccc_impl_fom_insert_or_assign_w(flat_ordered_map_ptr, key, lazy_value) \
    }

Inserts a new key value pair or overwrites the existing entry.

Parameters

[in]	flat_ordered_map_ptr	the pointer to the flat hash map.
[in]	key	the key to be searched in the map.
[in]	lazy_value	the compound literal to insert or use for overwrite.

Returns: a compound literal reference to the entry of the existing or newly inserted value. Occupied indicates the key existed, Vacant indicates the key was absent. Unwrapping in any case provides the current value unless an error occurs that prevents insertion. An insertion error will flag such a case.

Note that for brevity and convenience the user need not write the key to the lazy value compound literal as well. This function ensures the key in the compound literal matches the searched key.

◆ ccc_fom_insert_r

#define ccc_fom_insert_r	(	flat_ordered_map_ptr,
		out_handle_ptr
	)

Value:

    &(ccc_entry)                                                               \
    {                                                                          \
        ccc_fom_insert((flat_ordered_map_ptr), (out_handle_ptr)).impl_         \
    }

Invariantly inserts the key value wrapping key_val_handle.

Parameters

[in]	flat_ordered_map_ptr	the pointer to the ordered map.
[out]	out_handle_ptr	the handle to the user type wrapping map elem.

Returns: a compound literal reference to an entry. If Vacant, no prior element with key existed and the type wrapping out_handle remains unchanged. If Occupied the old value is written to the type wrapping out_handle and may be unwrapped to view. If more space is needed but allocation fails or has been forbidden, an insert error is set.

Note that this function may write to the struct containing out_handle and wraps it in an entry to provide information about the old value.

◆ ccc_fom_or_insert_w

#define ccc_fom_or_insert_w	(	flat_ordered_map_entry_ptr,
		lazy_key_value...
	)	ccc_impl_fom_or_insert_w(flat_ordered_map_entry_ptr, lazy_key_value)

Lazily insert the desired key value into the entry if it is Vacant.

Parameters

[in]	flat_ordered_map_entry_ptr	a pointer to the obtained entry.
[in]	lazy_key_value	the compound literal to construct in place if the entry is Vacant.

Returns: a reference to the unwrapped user type in the entry, either the unmodified reference if the entry was Occupied or the newly inserted element if the entry was Vacant. NULL is returned if resizing is required but fails or is not allowed.

Note that if the compound literal uses any function calls to generate values or other data, such functions will not be called if the entry is Occupied.

◆ ccc_fom_remove_entry_r

#define ccc_fom_remove_entry_r ( flat_ordered_map_entry_ptr )

Value:

    &(ccc_entry)                                                               \
    {                                                                          \
        ccc_fom_remove_entry((flat_ordered_map_entry_ptr)).impl_               \
    }

Remove the entry from the map if Occupied.

Parameters

[in] flat_ordered_map_entry_ptr a pointer to the map entry.

Returns: a compound literal reference to an entry containing NULL or a reference to the old entry. If Occupied an entry in the map existed and was removed. If Vacant, no prior entry existed to be removed.

Note that the reference to the removed entry is invalidated upon any further insertions.

◆ ccc_fom_remove_r

#define ccc_fom_remove_r	(	flat_ordered_map_ptr,
		out_handle_ptr
	)

Value:

    &(ccc_entry)                                                               \
    {                                                                          \
        ccc_fom_remove((flat_ordered_map_ptr), (out_handle_ptr)).impl_         \
    }

Removes the key value in the map storing the old value, if present, in the struct containing out_handle provided by the user.

Parameters

[in]	flat_ordered_map_ptr	the pointer to the ordered map.
[out]	out_handle_ptr	the handle to the user type wrapping map elem.

Returns: a compound literal reference to the removed entry. If Occupied it may be unwrapped to obtain the old key value pair. If Vacant the key value pair was not stored in the map. If bad input is provided an input error is set.

Note that this function may write to the struct containing the second parameter and wraps it in an entry to provide information about the old value.

◆ ccc_fom_try_insert_r

#define ccc_fom_try_insert_r	(	flat_ordered_map_ptr,
		key_val_handle_ptr
	)

Value:

    &(ccc_entry)                                                               \
    {                                                                          \
        ccc_fom_try_insert((flat_ordered_map_ptr), (key_val_handle_ptr)).impl_ \
    }

Attempts to insert the key value wrapping key_val_handle.

Parameters

[in]	flat_ordered_map_ptr	the pointer to the map.
[in]	key_val_handle_ptr	the handle to the user type wrapping map elem.

Returns: a compound literal reference to an entry. If Occupied, the entry contains a reference to the key value user type in the map and may be unwrapped. If Vacant the entry contains a reference to the newly inserted entry in the map. If more space is needed but allocation fails an insert error is set.

◆ ccc_fom_try_insert_w

#define ccc_fom_try_insert_w	(	flat_ordered_map_ptr,
		key,
		lazy_value...
	)

Value:

    &(ccc_entry)                                                               \
    {                                                                          \
        ccc_impl_fom_try_insert_w(flat_ordered_map_ptr, key, lazy_value)       \
    }

lazily insert lazy_value into the map at key if key is absent.

Parameters

[in]	flat_ordered_map_ptr	a pointer to the map.
[in]	key	the direct key r-value.
[in]	lazy_value	the compound literal specifying the value.

Returns: a compound literal reference to the entry of the existing or newly inserted value. Occupied indicates the key existed, Vacant indicates the key was absent. Unwrapping in any case provides the current value unless an error occurs that prevents insertion. An insertion error will flag such a case.

Note that for brevity and convenience the user need not write the key to the lazy value compound literal as well. This function ensures the key in the compound literal matches the searched key.

Typedef Documentation

◆ ccc_flat_ordered_map

typedef struct ccc_fomap_ ccc_flat_ordered_map

A self-optimizing data structure offering amortized O(lg N) search, insert, and erase.

Warning: it is undefined behavior to access an uninitialized container.

A flat ordered map can be initialized on the stack, heap, or data segment at runtime or compile time.

◆ ccc_fomap_elem

typedef struct ccc_fomap_elem_ ccc_fomap_elem

The intrusive element for the user defined type being stored in the map.

Note that if allocation is not permitted, insertions functions accepting this type as an argument assume it to exist in pre-allocated memory that will exist with the appropriate lifetime and scope for the user's needs; the container does not allocate or free in this case.

◆ ccc_fomap_entry

typedef union ccc_fomap_entry_ ccc_fomap_entry

A container specific entry used to implement the Entry Interface.

The Entry Interface offers efficient search and subsequent insertion, deletion, or value update based on the needs of the user.

Function Documentation

◆ ccc_fom_and_modify()

ccc_fomap_entry * ccc_fom_and_modify	(	ccc_fomap_entry *	e,
		ccc_update_fn *	fn
	)

Modifies the provided entry if it is Occupied.

Parameters

[in]	e	the entry obtained from an entry function or macro.
[in]	fn	an update function in which the auxiliary argument is unused.

Returns: the updated entry if it was Occupied or the unmodified vacant entry.

This function is intended to make the function chaining in the Entry Interface more succinct if the entry will be modified in place based on its own value without the need of the auxiliary argument a ccc_update_fn can provide.

◆ ccc_fom_and_modify_aux()

ccc_fomap_entry * ccc_fom_and_modify_aux	(	ccc_fomap_entry *	e,
		ccc_update_fn *	fn,
		void *	aux
	)

Modifies the provided entry if it is Occupied.

Parameters

[in]	e	the entry obtained from an entry function or macro.
[in]	fn	an update function that requires auxiliary data.
[in]	aux	auxiliary data required for the update.

Returns: the updated entry if it was Occupied or the unmodified vacant entry.

This function makes full use of a ccc_update_fn capability, meaning a complete ccc_update object will be passed to the update function callback.

◆ ccc_fom_begin()

void * ccc_fom_begin ( ccc_flat_ordered_map const * fom )

Return the start of an inorder traversal of the map. Amortized O(lg N).

Parameters

[in] fom a pointer to the map.

Returns: the oldest minimum element of the map.

◆ ccc_fom_capacity()

size_t ccc_fom_capacity ( ccc_flat_ordered_map const * fom )

Returns the capacity of the map.

Parameters

[in] fom the map.

Returns: the size_t capacity.

◆ ccc_fom_clear()

ccc_result ccc_fom_clear	(	ccc_flat_ordered_map *	fom,
		ccc_destructor_fn *	fn
	)

Frees all slots in the map for use without affecting capacity.

Parameters

[in]	fom	the map to be cleared.
[in]	fn	the destructor for each element. NULL can be passed if no maintenance is required on the elements in the map before their slots are forfeit.

If NULL is passed as the destructor function time is O(1), else O(size).

◆ ccc_fom_clear_and_free()

ccc_result ccc_fom_clear_and_free	(	ccc_flat_ordered_map *	fom,
		ccc_destructor_fn *	fn
	)

Frees all slots in the map and frees the underlying buffer.

Parameters

[in]	fom	the map to be cleared.
[in]	fn	the destructor for each element. NULL can be passed if no maintenance is required on the elements in the map before their slots are forfeit.

Returns: the result of free operation. If no alloc function is provided it is an error to attempt to free the buffer and a memory error is returned. Otherwise, an OK result is returned.

If NULL is passed as the destructor function time is O(1), else O(size).

◆ ccc_fom_contains()

bool ccc_fom_contains	(	ccc_flat_ordered_map *	fom,
		void const *	key
	)

Searches the map for the presence of key.

Parameters

[in]	fom	the map to be searched.
[in]	key	pointer to the key matching the key type of the user struct.

Returns: true if the struct containing key is stored, false if not.

◆ ccc_fom_copy()

ccc_result ccc_fom_copy	(	ccc_flat_ordered_map *	dst,
		ccc_flat_ordered_map const *	src,
		ccc_alloc_fn *	fn
	)

Copy the map at source to destination.

Parameters

[in]	dst	the initialized destination for the copy of the src map.
[in]	src	the initialized source of the map.
[in]	fn	the allocation function to resize dst or NULL.

Returns: the result of the copy operation. If the destination capacity is less than the source capacity and no allocation function is provided an input error is returned. If resizing is required and resizing of dst fails a memory error is returned.

Note: dst must have capacity greater than or equal to src. If dst capacity is less than src, an allocation function must be provided with the fn argument.

Note that there are two ways to copy data from source to destination: provide sufficient memory and pass NULL as fn, or allow the copy function to take care of allocation for the copy.

Manual memory management with no allocation function provided.

#define FLAT_ORDERED_MAP_USING_NAMESPACE_CCC
struct val
{
    fomap_elem e;
    int key;
    int val;
};
static flat_ordered_map src
    = fom_init((static struct val[11]){}, 11, e, key, NULL, key_cmp, NULL);
insert_rand_vals(&src);
static flat_ordered_map dst
    = fom_init((static struct val[13]){}, 13, e, key, NULL, key_cmp, NULL);
ccc_result res = fom_copy(&dst, &src, NULL);

The above requires dst capacity be greater than or equal to src capacity. Here is memory management handed over to the copy function.

#define FLAT_ORDERED_MAP_USING_NAMESPACE_CCC
struct val
{
    fomap_elem e;
    int key;
    int val;
};
static flat_ordered_map src
    = fom_init((struct val *)NULL, 0, e, key, std_alloc, key_cmp, NULL);
insert_rand_vals(&src);
static flat_ordered_map dst
    = fom_init((struct val *)NULL, 0, e, key, std_alloc, key_cmp, NULL);
ccc_result res = fom_copy(&dst, &src, std_alloc);

The above allows dst to have a capacity less than that of the src as long as copy has been provided an allocation function to resize dst. Note that this would still work if copying to a destination that the user wants as a fixed size map.

#define FLAT_ORDERED_MAP_USING_NAMESPACE_CCC
struct val
{
    fomap_elem e;
    int key;
    int val;
};
static flat_ordered_map src
    = fom_init((struct val *)NULL, 0, e, key, std_alloc, key_cmp, NULL);
insert_rand_vals(&src);
static flat_ordered_map dst
    = fom_init((struct val *)NULL, 0, e, key, NULL, key_cmp, NULL);
ccc_result res = fom_copy(&dst, &src, std_alloc);

The above sets up dst with fixed size while src is a dynamic map. Because an allocation function is provided, the dst is resized once for the copy and retains its fixed size after the copy is complete. This would require the user to manually free the underlying buffer at dst eventually if this method is used. Usually it is better to allocate the memory explicitly before the copy if copying between maps without allocation permission.

These options allow users to stay consistent across containers with their memory management strategies.

◆ ccc_fom_data()

void * ccc_fom_data ( ccc_flat_ordered_map const * fom )

Return a reference to the base of backing array. O(1).

Parameters

[in] fom a pointer to the map.

Returns: a reference to the base of the backing array.

Note: the reference is to the base of the backing array at index 0 with no consideration for the organization of map. However, all nodes of the map are guaranteed to be stored contiguously starting at index 1. Index 0 is reserved for the sentinel node.

Warning: it is the users responsibility to ensure that access to any data is within the capacity of the backing buffer.

◆ ccc_fom_end()

void * ccc_fom_end ( ccc_flat_ordered_map const * fom )

Return the end of an inorder traversal of the map. O(1).

Parameters

[in] fom a pointer to the map.

Returns: the newest maximum element of the map.

◆ ccc_fom_entry()

ccc_fomap_entry ccc_fom_entry	(	ccc_flat_ordered_map *	fom,
		void const *	key
	)

Obtains an entry for the provided key in the map for future use.

Parameters

[in]	fom	the map to be searched.
[in]	key	the key used to search the map matching the stored key type.

Returns: a specialized entry for use with other functions in the Entry Interface.

Warning: the contents of an entry should not be examined or modified. Use the provided functions, only.

An entry is a search result that provides either an Occupied or Vacant entry in the map. An occupied entry signifies that the search was successful. A Vacant entry means the search was not successful but a handle is gained to where in the map such an element should be inserted.

An entry is rarely useful on its own. It should be passed in a functional style to subsequent calls in the Entry Interface.

◆ ccc_fom_entry_status()

ccc_entry_status ccc_fom_entry_status ( ccc_fomap_entry const * e )

Obtain the entry status from a container entry.

Parameters

[in] e a pointer to the entry.

Returns: the status stored in the entry after the required action on the container completes. If e is NULL an entry input error is returned so ensure e is non-NULL to avoid an inaccurate status returned.

Note that this function can be useful for debugging or if more detailed messages are needed for logging purposes. See ccc_entry_status_msg() in ccc/types.h for more information on detailed entry statuses.

◆ ccc_fom_equal_range()

ccc_range ccc_fom_equal_range	(	ccc_flat_ordered_map *	fom,
		void const *	begin_key,
		void const *	end_key
	)

Return an iterable range of values from [begin_key, end_key). Amortized O(lg N).

Parameters

[in]	fom	a pointer to the map.
[in]	begin_key	a pointer to the key intended as the start of the range.
[in]	end_key	a pointer to the key intended as the end of the range.

Returns: a range containing the first element NOT LESS than the begin_key and the first element GREATER than end_key.

Note that due to the variety of values that can be returned in the range, using the provided range iteration functions from types.h is recommended for example:

for (struct val *i = range_begin(&range);
     i != end_range(&range);
     i = next(&fom, &i->elem))
{}

This avoids any possible errors in handling an end range element that is in the map versus the end map sentinel.

◆ ccc_fom_equal_rrange()

ccc_rrange ccc_fom_equal_rrange	(	ccc_flat_ordered_map *	fom,
		void const *	rbegin_key,
		void const *	rend_key
	)

Return an iterable rrange of values from [rbegin_key, end_key). Amortized O(lg N).

Parameters

[in]	fom	a pointer to the map.
[in]	rbegin_key	a pointer to the key intended as the start of the rrange.
[in]	rend_key	a pointer to the key intended as the end of the rrange.

Returns: a rrange containing the first element NOT GREATER than the begin_key and the first element LESS than rend_key.

Note that due to the variety of values that can be returned in the rrange, using the provided rrange iteration functions from types.h is recommended for example:

for (struct val *i = rrange_begin(&rrange);
     i != rend_rrange(&rrange);
     i = rnext(&fom, &i->elem))
{}

This avoids any possible errors in handling an rend rrange element that is in the map versus the end map sentinel.

◆ ccc_fom_get_key_val()

void * ccc_fom_get_key_val	(	ccc_flat_ordered_map *	fom,
		void const *	key
	)

Returns a reference into the map at entry key.

Parameters

[in]	fom	the ordered map to search.
[in]	key	the key to search matching stored key type.

Returns: a view of the map entry if it is present, else NULL.

◆ ccc_fom_insert()

ccc_entry ccc_fom_insert	(	ccc_flat_ordered_map *	fom,
		ccc_fomap_elem *	out_handle
	)

Invariantly inserts the key value wrapping key_val_handle.

Parameters

[in]	fom	the pointer to the ordered map.
[out]	out_handle	the handle to the user type wrapping map elem.

Returns: an entry. If Vacant, no prior element with key existed and the type wrapping out_handle remains unchanged. If Occupied the old value is written to the type wrapping out_handle and may be unwrapped to view. If more space is needed but allocation fails or has been forbidden, an insert error is set.

Note that this function may write to the struct containing out_handle and wraps it in an entry to provide information about the old value.

◆ ccc_fom_insert_entry()

void * ccc_fom_insert_entry	(	ccc_fomap_entry const *	e,
		ccc_fomap_elem *	elem
	)

Inserts the provided entry invariantly.

Parameters

[in]	e	the entry returned from a call obtaining an entry.
[in]	elem	a handle to the struct the user intends to insert.

Returns: a pointer to the inserted element or NULL upon allocation failure.

This method can be used when the old value in the map does not need to be preserved. See the regular insert method if the old value is of interest.

◆ ccc_fom_insert_error()

bool ccc_fom_insert_error ( ccc_fomap_entry const * e )

Provides the status of the entry should an insertion follow.

Parameters

[in] e the entry from a query to the table via function or macro.

Returns: true if an entry obtained from an insertion attempt failed to insert due to an allocation failure when allocation success was expected.

◆ ccc_fom_insert_or_assign()

ccc_entry ccc_fom_insert_or_assign	(	ccc_flat_ordered_map *	fom,
		ccc_fomap_elem *	key_val_handle
	)

Invariantly inserts or overwrites a user struct into the map.

Parameters

[in]	fom	a pointer to the flat hash map.
[in]	key_val_handle	the handle to the wrapping user struct key value.

Returns: an entry. If Occupied an entry was overwritten by the new key value. If Vacant no prior map entry existed.

Note that this function can be used when the old user type is not needed but the information regarding its presence is helpful.

◆ ccc_fom_is_empty()

bool ccc_fom_is_empty ( ccc_flat_ordered_map const * fom )

Returns the size status of the map.

Parameters

[in] fom the map.

Returns: true if empty else false.

◆ ccc_fom_next()

void * ccc_fom_next	(	ccc_flat_ordered_map const *	fom,
		ccc_fomap_elem const *	iter_handle
	)

Return the next element in an inorder traversal of the map. O(1).

Parameters

[in]	fom	a pointer to the map.
[in]	iter_handle	a pointer to the intrusive map element of the current iterator.

Returns: the next user type stored in the map in an inorder traversal.

◆ ccc_fom_occupied()

bool ccc_fom_occupied ( ccc_fomap_entry const * e )

Returns the Vacant or Occupied status of the entry.

Parameters

[in] e the entry from a query to the map via function or macro.

Returns: true if the entry is occupied, false if not.

◆ ccc_fom_or_insert()

void * ccc_fom_or_insert	(	ccc_fomap_entry const *	e,
		ccc_fomap_elem *	elem
	)

Inserts the struct with handle elem if the entry is Vacant.

Parameters

[in]	e	the entry obtained via function or macro call.
[in]	elem	the handle to the struct to be inserted to a Vacant entry.

Returns: a pointer to entry in the map invariantly. NULL on error.

Because this functions takes an entry and inserts if it is Vacant, the only reason NULL shall be returned is when an insertion error occurs, usually due to a user struct allocation failure.

If no allocation is permitted, this function assumes the user struct wrapping elem has been allocated with the appropriate lifetime and scope by the user.

◆ ccc_fom_rbegin()

void * ccc_fom_rbegin ( ccc_flat_ordered_map const * fom )

Return the start of a reverse inorder traversal of the map. Amortized O(lg N).

Parameters

[in] fom a pointer to the map.

Returns: the oldest maximum element of the map.

◆ ccc_fom_remove()

ccc_entry ccc_fom_remove	(	ccc_flat_ordered_map *	fom,
		ccc_fomap_elem *	out_handle
	)

Removes the key value in the map storing the old value, if present, in the struct containing out_handle provided by the user.

Parameters

[in]	fom	the pointer to the ordered map.
[out]	out_handle	the handle to the user type wrapping map elem.

Returns: the removed entry. If Occupied it may be unwrapped to obtain the old key value pair. If Vacant the key value pair was not stored in the map. If bad input is provided an input error is set.

Note that this function may write to the struct containing the second parameter and wraps it in an entry to provide information about the old value.

◆ ccc_fom_remove_entry()

ccc_entry ccc_fom_remove_entry ( ccc_fomap_entry * e )

Remove the entry from the map if Occupied.

Parameters

[in] e a pointer to the map entry.

Returns: an entry containing NULL or a reference to the old entry. If Occupied an entry in the map existed and was removed. If Vacant, no prior entry existed to be removed.

Note that the reference to the removed entry is invalidated upon any further insertions.

◆ ccc_fom_rend()

void * ccc_fom_rend ( ccc_flat_ordered_map const * fom )

Return the rend of a reverse inorder traversal of the map. O(1).

Parameters

[in] fom a pointer to the map.

Returns: the newest minimum element of the map.

◆ ccc_fom_rnext()

void * ccc_fom_rnext	(	ccc_flat_ordered_map const *	fom,
		ccc_fomap_elem const *	iter_handle
	)

Return the rnext element in a reverse inorder traversal of the map. O(1).

Parameters

[in]	fom	a pointer to the map.
[in]	iter_handle	a pointer to the intrusive map element of the current iterator.

Returns: the rnext user type stored in the map in a reverse inorder traversal.

◆ ccc_fom_size()

size_t ccc_fom_size ( ccc_flat_ordered_map const * fom )

Returns the size of the map.

Parameters

[in] fom the map.

Returns: the size_t size.

◆ ccc_fom_try_insert()

ccc_entry ccc_fom_try_insert	(	ccc_flat_ordered_map *	fom,
		ccc_fomap_elem *	key_val_handle
	)

Attempts to insert the key value wrapping key_val_handle.

Parameters

[in]	fom	the pointer to the map.
[in]	key_val_handle	the handle to the user type wrapping map elem.

Returns: an entry. If Occupied, the entry contains a reference to the key value user type in the map and may be unwrapped. If Vacant the entry contains a reference to the newly inserted entry in the map. If more space is needed but allocation fails, an insert error is set.

◆ ccc_fom_unwrap()

void * ccc_fom_unwrap ( ccc_fomap_entry const * e )

Unwraps the provided entry to obtain a view into the map element.

Parameters

[in] e the entry from a query to the map via function or macro.

Returns: a view into the table entry if one is present, or NULL.

◆ ccc_fom_validate()

bool ccc_fom_validate ( ccc_flat_ordered_map const * fom )

Validation of invariants for the map.

Parameters

[in] fom the map to validate.

Returns: true if all invariants hold, false if corruption occurs.

Initialization Interface

Entry Interface

Iterator Interface

Container Types

Membership Interface

Deallocation Interface

State Interface

Detailed Description

Macro Definition Documentation

◆ ccc_fom_and_modify_w

◆ ccc_fom_entry_r

◆ ccc_fom_equal_range_r

◆ ccc_fom_equal_rrange_r

◆ ccc_fom_init

◆ ccc_fom_insert_entry_w

◆ ccc_fom_insert_or_assign_w

◆ ccc_fom_insert_r

◆ ccc_fom_or_insert_w

◆ ccc_fom_remove_entry_r

◆ ccc_fom_remove_r

◆ ccc_fom_try_insert_r

◆ ccc_fom_try_insert_w

Typedef Documentation

◆ ccc_flat_ordered_map

◆ ccc_fomap_elem

◆ ccc_fomap_entry

Function Documentation

◆ ccc_fom_and_modify()

◆ ccc_fom_and_modify_aux()

◆ ccc_fom_begin()

◆ ccc_fom_capacity()

◆ ccc_fom_clear()

◆ ccc_fom_clear_and_free()

◆ ccc_fom_contains()

◆ ccc_fom_copy()

◆ ccc_fom_data()

◆ ccc_fom_end()

◆ ccc_fom_entry()

◆ ccc_fom_entry_status()

◆ ccc_fom_equal_range()

◆ ccc_fom_equal_rrange()

◆ ccc_fom_get_key_val()

◆ ccc_fom_insert()

◆ ccc_fom_insert_entry()

◆ ccc_fom_insert_error()

◆ ccc_fom_insert_or_assign()

◆ ccc_fom_is_empty()

◆ ccc_fom_next()

◆ ccc_fom_occupied()

◆ ccc_fom_or_insert()

◆ ccc_fom_rbegin()

◆ ccc_fom_remove()

◆ ccc_fom_remove_entry()

◆ ccc_fom_rend()

◆ ccc_fom_rnext()

◆ ccc_fom_size()

◆ ccc_fom_try_insert()

◆ ccc_fom_unwrap()

◆ ccc_fom_validate()