protobuf/upb/hash/int_table.h

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 * All rights reserved.
 *
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 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
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#ifndef UPB_HASH_INT_TABLE_H_
#define UPB_HASH_INT_TABLE_H_

#include "upb/hash/common.h"

// Must be last.
#include "upb/port/def.inc"

typedef struct {
  upb_table t;              // For entries that don't fit in the array part.
  const upb_tabval* array;  // Array part of the table. See const note above.
  size_t array_size;        // Array part size.
  size_t array_count;       // Array part number of elements.
} upb_inttable;

#ifdef __cplusplus
extern "C" {
#endif

// Initialize a table. If memory allocation failed, false is returned and
// the table is uninitialized.
bool upb_inttable_init(upb_inttable* table, upb_Arena* a);

// Returns the number of values in the table.
size_t upb_inttable_count(const upb_inttable* t);

// Inserts the given key into the hashtable with the given value.
// The key must not already exist in the hash table.
// The value must not be UINTPTR_MAX.
//
// If a table resize was required but memory allocation failed, false is
// returned and the table is unchanged.
bool upb_inttable_insert(upb_inttable* t, uintptr_t key, upb_value val,
                         upb_Arena* a);

// Looks up key in this table, returning "true" if the key was found.
// If v is non-NULL, copies the value for this key into *v.
bool upb_inttable_lookup(const upb_inttable* t, uintptr_t key, upb_value* v);

// Removes an item from the table. Returns true if the remove was successful,
// and stores the removed item in *val if non-NULL.
bool upb_inttable_remove(upb_inttable* t, uintptr_t key, upb_value* val);

// Updates an existing entry in an inttable.
// If the entry does not exist, returns false and does nothing.
// Unlike insert/remove, this does not invalidate iterators.
bool upb_inttable_replace(upb_inttable* t, uintptr_t key, upb_value val);

// Optimizes the table for the current set of entries, for both memory use and
// lookup time. Client should call this after all entries have been inserted;
// inserting more entries is legal, but will likely require a table resize.
void upb_inttable_compact(upb_inttable* t, upb_Arena* a);

/* Iteration over inttable.
 *
 *   intptr_t iter = UPB_INTTABLE_BEGIN;
 *   uintptr_t key;
 *   upb_value val;
 *   while (upb_inttable_next2(t, &key, &val, &iter)) {
 *      // ...
 *   }
 */

#define UPB_INTTABLE_BEGIN -1

bool upb_inttable_next2(const upb_inttable* t, uintptr_t* key, upb_value* val,
                        intptr_t* iter);
void upb_inttable_removeiter(upb_inttable* t, intptr_t* iter);

/* DEPRECATED iterators, slated for removal.
 *
 * Iterators for int tables.  We are subject to some kind of unusual
 * design constraints:
 *
 * For high-level languages:
 *  - we must be able to guarantee that we don't crash or corrupt memory even if
 *    the program accesses an invalidated iterator.
 *
 * For C++11 range-based for:
 *  - iterators must be copyable
 *  - iterators must be comparable
 *  - it must be possible to construct an "end" value.
 *
 * Iteration order is undefined.
 *
 * Modifying the table invalidates iterators.  upb_{str,int}table_done() is
 * guaranteed to work even on an invalidated iterator, as long as the table it
 * is iterating over has not been freed.  Calling next() or accessing data from
 * an invalidated iterator yields unspecified elements from the table, but it is
 * guaranteed not to crash and to return real table elements (except when done()
 * is true). */

/* upb_inttable_iter **********************************************************/

/*   upb_inttable_iter i;
 *   upb_inttable_begin(&i, t);
 *   for(; !upb_inttable_done(&i); upb_inttable_next(&i)) {
 *     uintptr_t key = upb_inttable_iter_key(&i);
 *     upb_value val = upb_inttable_iter_value(&i);
 *     // ...
 *   }
 */

typedef struct {
  const upb_inttable* t;
  size_t index;
  bool array_part;
} upb_inttable_iter;

void upb_inttable_begin(upb_inttable_iter* i, const upb_inttable* t);
void upb_inttable_next(upb_inttable_iter* i);
bool upb_inttable_done(const upb_inttable_iter* i);
uintptr_t upb_inttable_iter_key(const upb_inttable_iter* i);
upb_value upb_inttable_iter_value(const upb_inttable_iter* i);
void upb_inttable_iter_setdone(upb_inttable_iter* i);
bool upb_inttable_iter_isequal(const upb_inttable_iter* i1,
                               const upb_inttable_iter* i2);

#ifdef __cplusplus
} /* extern "C" */
#endif

#include "upb/port/undef.inc"

#endif /* UPB_HASH_INT_TABLE_H_ */