/src/croaring/include/roaring/roaring.h

Source
/*
 * An implementation of Roaring Bitmaps in C.
 *
 * This is the main public header for the 32-bit CRoaring API. A Roaring bitmap
 * represents a set of unsigned 32-bit integers by partitioning the value space
 * into 16-bit chunks and storing each chunk in a container chosen to match the
 * local data density. Sparse chunks are typically kept as sorted arrays,
 * denser chunks as bitsets, and long consecutive runs as run containers.
 *
 * This hybrid representation aims to keep bitmaps compact while still
 * supporting fast membership tests, iteration, rank/select queries,
 * serialization, and set operations such as union, intersection, difference,
 * and symmetric difference.
 */

#ifndef ROARING_H
#define ROARING_H

#include <stdbool.h>
#include <stddef.h>  // for `size_t`
#include <stdint.h>

#include <roaring/roaring_types.h>

// Include other headers after roaring_types.h
#include <roaring/bitset/bitset.h>
#include <roaring/containers/containers.h>
#include <roaring/memory.h>
#include <roaring/portability.h>
#include <roaring/roaring_array.h>
#include <roaring/roaring_version.h>

#ifdef __cplusplus
extern "C" {
namespace roaring {
namespace api {
#endif

typedef struct roaring_bitmap_s {
    roaring_array_t high_low_container;
} roaring_bitmap_t;

/**
 * Dynamically allocates a new bitmap (initially empty).
 * Returns NULL if the allocation fails.
 * Capacity is a performance hint for how many "containers" the data will need.
 * Client is responsible for calling `roaring_bitmap_free()`.
 */
roaring_bitmap_t *roaring_bitmap_create_with_capacity(uint32_t cap);

/**
 * Dynamically allocates a new bitmap (initially empty).
 * Returns NULL if the allocation fails.
 * Client is responsible for calling `roaring_bitmap_free()`.
 */
inline roaring_bitmap_t *roaring_bitmap_create(void) {
    return roaring_bitmap_create_with_capacity(0);
}

/**
 * Initialize a roaring bitmap structure in memory controlled by client.
 * Capacity is a performance hint for how many "containers" the data will need.
 * Can return false if auxiliary allocations fail when capacity greater than 0.
 */
bool roaring_bitmap_init_with_capacity(roaring_bitmap_t *r, uint32_t cap);

/**
 * Initialize a roaring bitmap structure in memory controlled by client.
 * The bitmap will be in a "clear" state, with no auxiliary allocations.
 * Since this performs no allocations, the function will not fail.
 */
inline void roaring_bitmap_init_cleared(roaring_bitmap_t *r) {
    roaring_bitmap_init_with_capacity(r, 0);
}

/**
 * Add all the values between min (included) and max (excluded) that are at a
 * distance k*step from min.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_from_range(uint64_t min, uint64_t max,
                                            uint32_t step);

/**
 * Creates a new bitmap from a pointer of uint32_t integers
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_of_ptr(size_t n_args, const uint32_t *vals);

/**
 * Check if the bitmap contains any shared containers.
 */
bool roaring_contains_shared(const roaring_bitmap_t *r);

/**
 * Unshare all shared containers.
 * Returns true if any unsharing was performed, false if there were no shared
 * containers.
 */
bool roaring_unshare_all(roaring_bitmap_t *r);

/*
 * Whether you want to use copy-on-write.
 * Saves memory and avoids copies, but needs more care in a threaded context.
 * Most users should ignore this flag.
 *
 * Note: If you do turn this flag to 'true', enabling COW, then ensure that you
 * do so for all of your bitmaps, since interactions between bitmaps with and
 * without COW is unsafe.
 *
 * When setting this flag to false, if any containers are shared, they
 * are unshared (cloned) immediately.
 */
inline bool roaring_bitmap_get_copy_on_write(const roaring_bitmap_t *r) {
    return r->high_low_container.flags & ROARING_FLAG_COW;
}
inline void roaring_bitmap_set_copy_on_write(roaring_bitmap_t *r, bool cow) {
    if (cow) {
        r->high_low_container.flags |= ROARING_FLAG_COW;
    } else {
        if (roaring_bitmap_get_copy_on_write(r)) {
            roaring_unshare_all(r);
        }
        r->high_low_container.flags &= ~ROARING_FLAG_COW;
    }
}

/**
 * Return a copy of the bitmap with all values shifted by offset.
 * The returned pointer may be NULL in case of errors. The caller is responsible
 * for freeing the return bitmap.
 */
roaring_bitmap_t *roaring_bitmap_add_offset(const roaring_bitmap_t *bm,
                                            int64_t offset);
/**
 * Describe the inner structure of the bitmap.
 */
void roaring_bitmap_printf_describe(const roaring_bitmap_t *r);

/**
 * Creates a new bitmap from a list of uint32_t integers
 *
 * This function is deprecated, use `roaring_bitmap_from` instead, which
 * doesn't require the number of elements to be passed in.
 *
 * @see roaring_bitmap_from
 */
CROARING_DEPRECATED roaring_bitmap_t *roaring_bitmap_of(size_t n, ...);

#ifdef __cplusplus
/**
 * Creates a new bitmap which contains all values passed in as arguments.
 *
 * To create a bitmap from a variable number of arguments, use the
 * `roaring_bitmap_of_ptr` function instead.
 */
// Use an immediately invoked closure, capturing by reference
// (in case __VA_ARGS__ refers to context outside the closure)
// Include a 0 at the beginning of the array to make the array length > 0
// (zero sized arrays are not valid in standard c/c++)
#define roaring_bitmap_from(...)                                              \
    [&]() {                                                                   \
        const uint32_t roaring_bitmap_from_array[] = {0, __VA_ARGS__};        \
        return roaring_bitmap_of_ptr((sizeof(roaring_bitmap_from_array) /     \
                                      sizeof(roaring_bitmap_from_array[0])) - \
                                         1,                                   \
                                     &roaring_bitmap_from_array[1]);          \
    }()
#else
/**
 * Creates a new bitmap which contains all values passed in as arguments.
 *
 * To create a bitmap from a variable number of arguments, use the
 * `roaring_bitmap_of_ptr` function instead.
 */
// While __VA_ARGS__ occurs twice in expansion, one of the times is in a sizeof
// expression, which is an unevaluated context, so it's even safe in the case
// where expressions passed have side effects (roaring64_bitmap_from(my_func(),
// ++i))
// Include a 0 at the beginning of the array to make the array length > 0
// (zero sized arrays are not valid in standard c/c++)
#define roaring_bitmap_from(...)                                             \
    roaring_bitmap_of_ptr(                                                   \
        (sizeof((const uint32_t[]){0, __VA_ARGS__}) / sizeof(uint32_t)) - 1, \
        &((const uint32_t[]){0, __VA_ARGS__})[1])
#endif

/**
 * Copies a bitmap (this does memory allocation).
 * The caller is responsible for memory management.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_copy(const roaring_bitmap_t *r);

/**
 * Copies a bitmap from src to dest. It is assumed that the pointer dest
 * is to an already allocated bitmap. The content of the dest bitmap is
 * freed/deleted.
 *
 * It might be preferable and simpler to call roaring_bitmap_copy except
 * that roaring_bitmap_overwrite can save on memory allocations.
 *
 * Returns true if successful, or false if there was an error. On failure,
 * the dest bitmap is left in a valid, empty state (even if it was not empty
 * before).
 */
bool roaring_bitmap_overwrite(roaring_bitmap_t *dest,
                              const roaring_bitmap_t *src);

/**
 * Print the content of the bitmap.
 */
void roaring_bitmap_printf(const roaring_bitmap_t *r);

/**
 * Computes the intersection between two bitmaps and returns new bitmap. The
 * caller is responsible for memory management.
 *
 * Performance hint: if you are computing the intersection between several
 * bitmaps, two-by-two, it is best to start with the smallest bitmap.
 * You may also rely on roaring_bitmap_and_inplace to avoid creating
 * many temporary bitmaps.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_and(const roaring_bitmap_t *r1,
                                     const roaring_bitmap_t *r2);

/**
 * Computes the size of the intersection between two bitmaps.
 */
uint64_t roaring_bitmap_and_cardinality(const roaring_bitmap_t *r1,
                                        const roaring_bitmap_t *r2);

/**
 * Check whether two bitmaps intersect.
 */
bool roaring_bitmap_intersect(const roaring_bitmap_t *r1,
                              const roaring_bitmap_t *r2);

/**
 * Check whether a bitmap and an open range intersect.
 */
bool roaring_bitmap_intersect_with_range(const roaring_bitmap_t *bm, uint64_t x,
                                         uint64_t y);

/**
 * Computes the Jaccard index between two bitmaps. (Also known as the Tanimoto
 * distance, or the Jaccard similarity coefficient)
 *
 * The Jaccard index is undefined if both bitmaps are empty.
 */
double roaring_bitmap_jaccard_index(const roaring_bitmap_t *r1,
                                    const roaring_bitmap_t *r2);

/**
 * Computes the size of the union between two bitmaps.
 */
uint64_t roaring_bitmap_or_cardinality(const roaring_bitmap_t *r1,
                                       const roaring_bitmap_t *r2);

/**
 * Computes the size of the difference (andnot) between two bitmaps.
 */
uint64_t roaring_bitmap_andnot_cardinality(const roaring_bitmap_t *r1,
                                           const roaring_bitmap_t *r2);

/**
 * Computes the size of the symmetric difference (xor) between two bitmaps.
 */
uint64_t roaring_bitmap_xor_cardinality(const roaring_bitmap_t *r1,
                                        const roaring_bitmap_t *r2);

/**
 * Inplace version of `roaring_bitmap_and()`, modifies r1
 * r1 == r2 is allowed.
 *
 * Performance hint: if you are computing the intersection between several
 * bitmaps, two-by-two, it is best to start with the smallest bitmap.
 */
void roaring_bitmap_and_inplace(roaring_bitmap_t *r1,
                                const roaring_bitmap_t *r2);

/**
 * Computes the union between two bitmaps and returns new bitmap. The caller is
 * responsible for memory management.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_or(const roaring_bitmap_t *r1,
                                    const roaring_bitmap_t *r2);

/**
 * Inplace version of `roaring_bitmap_or(), modifies r1.
 * TODO: decide whether r1 == r2 ok
 */
void roaring_bitmap_or_inplace(roaring_bitmap_t *r1,
                               const roaring_bitmap_t *r2);

/**
 * Compute the union of 'number' bitmaps.
 * Caller is responsible for freeing the result.
 * See also `roaring_bitmap_or_many_heap()`
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_or_many(size_t number,
                                         const roaring_bitmap_t **rs);

/**
 * Compute the union of 'number' bitmaps using a heap. This can sometimes be
 * faster than `roaring_bitmap_or_many() which uses a naive algorithm.
 * Caller is responsible for freeing the result.
 */
roaring_bitmap_t *roaring_bitmap_or_many_heap(uint32_t number,
                                              const roaring_bitmap_t **rs);

/**
 * Computes the symmetric difference (xor) between two bitmaps
 * and returns new bitmap. The caller is responsible for memory management.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_xor(const roaring_bitmap_t *r1,
                                     const roaring_bitmap_t *r2);

/**
 * Inplace version of roaring_bitmap_xor, modifies r1, r1 != r2.
 */
void roaring_bitmap_xor_inplace(roaring_bitmap_t *r1,
                                const roaring_bitmap_t *r2);

/**
 * Compute the xor of 'number' bitmaps.
 * Caller is responsible for freeing the result.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_xor_many(size_t number,
                                          const roaring_bitmap_t **rs);

/**
 * Computes the difference (andnot) between two bitmaps and returns new bitmap.
 * Caller is responsible for freeing the result.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_andnot(const roaring_bitmap_t *r1,
                                        const roaring_bitmap_t *r2);

/**
 * Inplace version of roaring_bitmap_andnot, modifies r1, r1 != r2.
 */
void roaring_bitmap_andnot_inplace(roaring_bitmap_t *r1,
                                   const roaring_bitmap_t *r2);

/**
 * TODO: consider implementing:
 *
 * "Compute the xor of 'number' bitmaps using a heap. This can sometimes be
 *  faster than roaring_bitmap_xor_many which uses a naive algorithm. Caller is
 *  responsible for freeing the result.""
 *
 * roaring_bitmap_t *roaring_bitmap_xor_many_heap(uint32_t number,
 *                                                const roaring_bitmap_t **rs);
 */

/**
 * Frees the memory.
 */
void roaring_bitmap_free(const roaring_bitmap_t *r);

/**
 * A bit of context usable with `roaring_bitmap_*_bulk()` functions
 *
 * Should be initialized with `{0}` (or `memset()` to all zeros).
 * Callers should treat it as an opaque type.
 *
 * A context may only be used with a single bitmap
 * (unless re-initialized to zero), and any modification to a bitmap
 * (other than modifications performed with `_bulk()` functions with the context
 * passed) will invalidate any contexts associated with that bitmap.
 */
typedef struct roaring_bulk_context_s {
    ROARING_CONTAINER_T *container;
    int idx;
    uint16_t key;
    uint8_t typecode;
} roaring_bulk_context_t;

/**
 * Add an item, using context from a previous insert for speed optimization.
 *
 * `context` will be used to store information between calls to make bulk
 * operations faster. `*context` should be zero-initialized before the first
 * call to this function.
 *
 * Modifying the bitmap in any way (other than `-bulk` suffixed functions)
 * will invalidate the stored context, calling this function with a non-zero
 * context after doing any modification invokes undefined behavior.
 *
 * In order to exploit this optimization, the caller should call this function
 * with values with the same "key" (high 16 bits of the value) consecutively.
 */
void roaring_bitmap_add_bulk(roaring_bitmap_t *r,
                             roaring_bulk_context_t *context, uint32_t val);

/**
 * Add value n_args from pointer vals, faster than repeatedly calling
 * `roaring_bitmap_add()`
 *
 * In order to exploit this optimization, the caller should attempt to keep
 * values with the same "key" (high 16 bits of the value) as consecutive
 * elements in `vals`
 */
void roaring_bitmap_add_many(roaring_bitmap_t *r, size_t n_args,
                             const uint32_t *vals);

/**
 * Add value x
 */
void roaring_bitmap_add(roaring_bitmap_t *r, uint32_t x);

/**
 * Add value x
 * Returns true if a new value was added, false if the value already existed.
 */
bool roaring_bitmap_add_checked(roaring_bitmap_t *r, uint32_t x);

/**
 * Add all values in range [min, max]
 */
void roaring_bitmap_add_range_closed(roaring_bitmap_t *r, uint32_t min,
                                     uint32_t max);

/**
 * Add all values in range [min, max)
 */
inline void roaring_bitmap_add_range(roaring_bitmap_t *r, uint64_t min,
                                     uint64_t max) {
    if (max <= min || min > (uint64_t)UINT32_MAX + 1) {
        return;
    }
    roaring_bitmap_add_range_closed(r, (uint32_t)min, (uint32_t)(max - 1));
}

/**
 * Remove value x
 */
void roaring_bitmap_remove(roaring_bitmap_t *r, uint32_t x);

/**
 * Remove all values in range [min, max]
 */
void roaring_bitmap_remove_range_closed(roaring_bitmap_t *r, uint32_t min,
                                        uint32_t max);

/**
 * Remove all values in range [min, max)
 */
inline void roaring_bitmap_remove_range(roaring_bitmap_t *r, uint64_t min,
                                        uint64_t max) {
    if (max <= min || min > (uint64_t)UINT32_MAX + 1) {
        return;
    }
    roaring_bitmap_remove_range_closed(r, (uint32_t)min, (uint32_t)(max - 1));
}

/**
 * Remove multiple values
 */
void roaring_bitmap_remove_many(roaring_bitmap_t *r, size_t n_args,
                                const uint32_t *vals);

/**
 * Remove value x
 * Returns true if a new value was removed, false if the value was not existing.
 */
bool roaring_bitmap_remove_checked(roaring_bitmap_t *r, uint32_t x);

/**
 * Check if value is present
 */
inline bool roaring_bitmap_contains(const roaring_bitmap_t *r, uint32_t val) {
    // For performance reasons, this function is inline and uses internal
    // functions directly.
#ifdef __cplusplus
    using namespace ::roaring::internal;
#endif
    const uint16_t hb = val >> 16;
    /*
     * the next function call involves a binary search and lots of branching.
     */
    int32_t i = ra_get_index(&r->high_low_container, hb);
    if (i < 0) return false;

    uint8_t typecode;
    // next call ought to be cheap
    container_t *container = ra_get_container_at_index(&r->high_low_container,
                                                       (uint16_t)i, &typecode);
    // rest might be a tad expensive, possibly involving another round of binary
    // search
    return container_contains(container, val & 0xFFFF, typecode);
}

/**
 * Check whether a range of values from range_start (included)
 * to range_end (excluded) is present
 */
bool roaring_bitmap_contains_range(const roaring_bitmap_t *r,
                                   uint64_t range_start, uint64_t range_end);

/**
 * Check whether a range of values from range_start (included)
 * to range_end (included) is present
 */
bool roaring_bitmap_contains_range_closed(const roaring_bitmap_t *r,
                                          uint32_t range_start,
                                          uint32_t range_end);

/**
 * Check if an items is present, using context from a previous insert or search
 * for speed optimization.
 *
 * `context` will be used to store information between calls to make bulk
 * operations faster. `*context` should be zero-initialized before the first
 * call to this function.
 *
 * Modifying the bitmap in any way (other than `-bulk` suffixed functions)
 * will invalidate the stored context, calling this function with a non-zero
 * context after doing any modification invokes undefined behavior.
 *
 * In order to exploit this optimization, the caller should call this function
 * with values with the same "key" (high 16 bits of the value) consecutively.
 */
bool roaring_bitmap_contains_bulk(const roaring_bitmap_t *r,
                                  roaring_bulk_context_t *context,
                                  uint32_t val);

/**
 * Get the cardinality of the bitmap (number of elements).
 */
uint64_t roaring_bitmap_get_cardinality(const roaring_bitmap_t *r);

/**
 * Returns the number of elements in the range [range_start, range_end).
 */
uint64_t roaring_bitmap_range_cardinality(const roaring_bitmap_t *r,
                                          uint64_t range_start,
                                          uint64_t range_end);

/**
 * Returns the number of elements in the range [range_start, range_end].
 */
uint64_t roaring_bitmap_range_cardinality_closed(const roaring_bitmap_t *r,
                                                 uint32_t range_start,
                                                 uint32_t range_end);
/**
 * Returns true if the bitmap is empty (cardinality is zero).
 */
bool roaring_bitmap_is_empty(const roaring_bitmap_t *r);

/**
 * Empties the bitmap.  It will have no auxiliary allocations (so if the bitmap
 * was initialized in client memory via roaring_bitmap_init(), then a call to
 * roaring_bitmap_clear() would be enough to "free" it)
 */
void roaring_bitmap_clear(roaring_bitmap_t *r);

/**
 * Convert the bitmap to a sorted array, output in `ans`.
 *
 * Caller is responsible to ensure that there is enough memory allocated, e.g.
 *
 *     ans = malloc(roaring_bitmap_get_cardinality(bitmap) * sizeof(uint32_t));
 */
void roaring_bitmap_to_uint32_array(const roaring_bitmap_t *r, uint32_t *ans);

/**
 * Store the bitmap to a bitset. This can be useful for people
 * who need the performance and simplicity of a standard bitset.
 * We assume that the input bitset is originally empty (does not
 * have any set bit).
 *
 *   bitset_t * out = bitset_create();
 *   // if the bitset has content in it, call "bitset_clear(out)"
 *   bool success = roaring_bitmap_to_bitset(mybitmap, out);
 *   // on failure, success will be false.
 *   // You can then query the bitset:
 *   bool is_present = bitset_get(out,  10011 );
 *   // you must free the memory:
 *   bitset_free(out);
 *
 */
bool roaring_bitmap_to_bitset(const roaring_bitmap_t *r, bitset_t *bitset);

/**
 * Writes the values of the bitmap in a range of 64-bit words, from
 * 64 * first_word (included) to 64 * (first_word + n_words) (excluded), as a
 * bitset in `words`: value 64 * (first_word + k) + i, if present, sets bit i
 * of words[k]. All n_words words are written (the caller does not need to zero
 * them). The cost is proportional to n_words plus the number of values and
 * runs in the range, not to the size of the bitmap.
 *
 * first_word + n_words must be at most 2^26 (that is, 2^32 / 64).
 *
 *   uint64_t words[16];
 *   // values 1024 to 2047, value 1024 + 64 * k + i in bit i of words[k]
 *   roaring_bitmap_word_range_to_bitset(mybitmap, 16, 16, words);
 */
void roaring_bitmap_word_range_to_bitset(const roaring_bitmap_t *r,
                                         uint32_t first_word, uint32_t n_words,
                                         uint64_t *words);

/**
 * Convert the bitmap to a sorted array from `offset` by `limit`, output in
 * `ans`.
 *
 * Caller is responsible to ensure that there is enough memory allocated, e.g.
 *
 *     ans = malloc(roaring_bitmap_get_cardinality(limit) * sizeof(uint32_t));
 *
 * This function always returns `true`
 *
 * For more control, see `roaring_uint32_iterator_skip` and
 * `roaring_uint32_iterator_read`, which can be used to e.g. tell how many
 * values were actually read.
 */
bool roaring_bitmap_range_uint32_array(const roaring_bitmap_t *r, size_t offset,
                                       size_t limit, uint32_t *ans);

/**
 * Remove run-length encoding even when it is more space efficient.
 * Return whether a change was applied.
 */
bool roaring_bitmap_remove_run_compression(roaring_bitmap_t *r);

/**
 * Convert array and bitmap containers to run containers when it is more
 * efficient; also convert from run containers when more space efficient.
 *
 * Returns true if the result has at least one run container.
 * Additional savings might be possible by calling `shrinkToFit()`.
 */
bool roaring_bitmap_run_optimize(roaring_bitmap_t *r);

/**
 * If needed, reallocate memory to shrink the memory usage.
 * Returns the number of bytes saved.
 */
size_t roaring_bitmap_shrink_to_fit(roaring_bitmap_t *r);

/**
 * Write the bitmap to an output pointer, this output buffer should refer to
 * at least `roaring_bitmap_size_in_bytes(r)` allocated bytes.
 *
 * See `roaring_bitmap_portable_serialize()` if you want a format that's
 * compatible with Java and Go implementations.  This format can sometimes be
 * more space efficient than the portable form, e.g. when the data is sparse.
 *
 * Returns how many bytes written, should be `roaring_bitmap_size_in_bytes(r)`.
 *
 * When serializing data to a file, we recommend that you also use
 * checksums so that, at deserialization, you can be confident
 * that you are recovering the correct data.
 */
size_t roaring_bitmap_serialize(const roaring_bitmap_t *r, char *buf);

/**
 * Use with `roaring_bitmap_serialize()`.
 *
 * (See `roaring_bitmap_portable_deserialize()` if you want a format that's
 * compatible with Java and Go implementations).
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_deserialize(const void *buf);

/**
 * Load a bitmap from a serialized buffer safely (reading up to maxbytes).
 *
 * Use with `roaring_bitmap_serialize()`.
 *
 * (See `roaring_bitmap_portable_deserialize_safe()` if you want a format that's
 * compatible with Java and Go implementations).
 *
 * The difference with `roaring_bitmap_deserialize()` is that this function
 * is guaranteed to not read beyond the provided buffer. If the buffer is too
 * small, NULL is returned.
 *
 * The function itself is safe in the sense that it will not cause buffer
 * overflows: it will not read beyond the scope of the provided buffer
 * (buf,maxbytes).
 *
 * However, for correct operations, it is assumed that the bitmap
 * read was once serialized from a valid bitmap (i.e., it follows the format
 * specification). If you provided an incorrect input (garbage), then the bitmap
 * read may not be in a valid state and following operations may not lead to
 * sensible results (using it may cause crashes, or it may just give incoherent
 * answers). You can call roaring_bitmap_internal_validate to check the validity
 * of the bitmap if the source is untrusted. Only after calling
 * roaring_bitmap_internal_validate is the bitmap considered safe for use.
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_deserialize_safe(const void *buf,
                                                  size_t maxbytes);

/**
 * How many bytes are required to serialize this bitmap (NOT compatible
 * with Java and Go versions)
 */
size_t roaring_bitmap_size_in_bytes(const roaring_bitmap_t *r);

/**
 * Read bitmap from a serialized buffer.
 * In case of failure, NULL is returned.
 *
 * This function is unsafe in the sense that if there is no valid serialized
 * bitmap at the pointer, then many bytes could be read, possibly causing a
 * buffer overflow. In other words, this routine assumes that `buf` points to a
 * complete, correctly formatted serialized bitmap and does not take a buffer
 * length argument that would let it enforce a read bound.
 *
 * Use this function only when the input buffer is already trusted, for example
 * because it comes from memory that was previously filled by
 * `roaring_bitmap_portable_serialize()` and whose size is known by some other
 * means. If the source is untrusted, truncated, or otherwise not guaranteed to
 * contain a valid serialized bitmap, prefer
 * `roaring_bitmap_portable_deserialize_safe()`.
 *
 * This is meant to be compatible with the Java and Go versions:
 * https://github.com/RoaringBitmap/RoaringFormatSpec
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_portable_deserialize(const char *buf);

/**
 * Read bitmap from a serialized buffer safely (reading up to maxbytes).
 * In case of failure, NULL is returned.
 *
 * This is meant to be compatible with the Java and Go versions:
 * https://github.com/RoaringBitmap/RoaringFormatSpec
 *
 * The function itself is safe in the sense that it will not cause buffer
 * overflows: it will not read beyond the scope of the provided buffer
 * (buf,maxbytes).
 *
 * However, for correct operations, it is assumed that the bitmap
 * read was once serialized from a valid bitmap (i.e., it follows the format
 * specification). If you provided an incorrect input (garbage), then the bitmap
 * read may not be in a valid state and following operations may not lead to
 * sensible results. In particular, the serialized array containers need to be
 * in sorted order, and the run containers should be in sorted non-overlapping
 * order. This is is guaranteed to happen when serializing an existing bitmap,
 * but not for random inputs.
 *
 * If the source is untrusted, you should call
 * roaring_bitmap_internal_validate to check the validity of the
 * bitmap prior to using it. Only after calling roaring_bitmap_internal_validate
 * is the bitmap considered safe for use.
 *
 * We also recommend that you use checksums to check that serialized data
 * corresponds to the serialized bitmap. The CRoaring library does not provide
 * checksumming.
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_portable_deserialize_safe(const char *buf,
                                                           size_t maxbytes);

/**
 * Read bitmap from a serialized buffer.
 * In case of failure, NULL is returned.
 *
 * Bitmap returned by this function can be used in all readonly contexts.
 * Bitmap must be freed as usual, by calling roaring_bitmap_free().
 * Underlying buffer must not be freed or modified while it backs any bitmaps.
 *
 * The function is unsafe in the following ways:
 * 1) It may execute unaligned memory accesses.
 * 2) A buffer overflow may occur if buf does not point to a valid serialized
 *    bitmap.
 *
 * This is meant to be compatible with the Java and Go versions:
 * https://github.com/RoaringBitmap/RoaringFormatSpec
 *
 * Returns NULL on a big-endian system (e.g., a mainframe IBM s390x). The
 * portable format is little-endian on every host, and this function uses the
 * container payloads where they sit rather than converting them, so there is
 * no correct in-place view of them there. Use
 * `roaring_bitmap_portable_deserialize_safe()`, which converts as it copies.
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_portable_deserialize_frozen(const char *buf);

/**
 * Check how many bytes would be read (up to maxbytes) at this pointer if there
 * is a bitmap, returns zero if there is no valid bitmap.
 *
 * This is meant to be compatible with the Java and Go versions:
 * https://github.com/RoaringBitmap/RoaringFormatSpec
 */
size_t roaring_bitmap_portable_deserialize_size(const char *buf,
                                                size_t maxbytes);

/**
 * How many bytes are required to serialize this bitmap.
 *
 * This is meant to be compatible with the Java and Go versions:
 * https://github.com/RoaringBitmap/RoaringFormatSpec
 */
size_t roaring_bitmap_portable_size_in_bytes(const roaring_bitmap_t *r);

/**
 * Write a bitmap to a char buffer.  The output buffer should refer to at least
 * `roaring_bitmap_portable_size_in_bytes(r)` bytes of allocated memory.
 *
 * Returns how many bytes were written which should match
 * `roaring_bitmap_portable_size_in_bytes(r)`.
 *
 * This is meant to be compatible with the Java and Go versions:
 * https://github.com/RoaringBitmap/RoaringFormatSpec
 *
 * When serializing data to a file, we recommend that you also use
 * checksums so that, at deserialization, you can be confident
 * that you are recovering the correct data.
 */
size_t roaring_bitmap_portable_serialize(const roaring_bitmap_t *r, char *buf);

/*
 * "Frozen" serialization format imitates memory layout of roaring_bitmap_t.
 * Deserialized bitmap is a constant view of the underlying buffer.
 * This significantly reduces amount of allocations and copying required during
 * deserialization.
 * It can be used with memory mapped files.
 * Example can be found in benchmarks/frozen_benchmark.c
 *
 *         [#####] const roaring_bitmap_t *
 *          | | |
 *     +----+ | +-+
 *     |      |   |
 * [#####################################] underlying buffer
 *
 * Note that because frozen serialization format imitates C memory layout
 * of roaring_bitmap_t, it is not fixed. It is different on big/little endian
 * platforms and can be changed in future.
 */

/**
 * Returns number of bytes required to serialize bitmap using frozen format.
 */
size_t roaring_bitmap_frozen_size_in_bytes(const roaring_bitmap_t *r);

/**
 * Serializes bitmap using frozen format.
 * Buffer size must be at least roaring_bitmap_frozen_size_in_bytes().
 *
 * This function is endian-sensitive. If you have a big-endian system (e.g., a
 * mainframe IBM s390x), the data format is going to be big-endian and not
 * compatible with little-endian systems. This is not a bug, it is by design,
 *since the format imitates C memory layout
 *
 * When serializing data to a file, we recommend that you also use
 * checksums so that, at deserialization, you can be confident
 * that you are recovering the correct data.
 */
void roaring_bitmap_frozen_serialize(const roaring_bitmap_t *r, char *buf);

/**
 * Creates constant bitmap that is a view of a given buffer.
 * Buffer data should have been written by `roaring_bitmap_frozen_serialize()`
 * Its beginning must also be aligned by 32 bytes.
 * Length must be equal exactly to `roaring_bitmap_frozen_size_in_bytes()`.
 * In case of failure, NULL is returned.
 *
 * Bitmap returned by this function can be used in all readonly contexts.
 * Bitmap must be freed as usual, by calling roaring_bitmap_free().
 * Underlying buffer must not be freed or modified while it backs any bitmaps.
 *
 * This function is endian-sensitive. If you have a big-endian system (e.g., a
 * mainframe IBM s390x), the data format is going to be big-endian and not
 * compatible with little-endian systems. This is not a bug, it is by design,
 *since the format imitates C memory layout of roaring_bitmap_t.
 */
const roaring_bitmap_t *roaring_bitmap_frozen_view(const char *buf,
                                                   size_t length);

/**
 * Iterate over the bitmap elements. The function iterator is called once for
 * all the values with ptr (can be NULL) as the second parameter of each call.
 *
 * `roaring_iterator` is simply a pointer to a function that returns bool
 * (true means that the iteration should continue while false means that it
 * should stop), and takes (uint32_t,void*) as inputs.
 *
 * Returns true if the roaring_iterator returned true throughout (so that all
 * data points were necessarily visited).
 *
 * Iteration is ordered: from the smallest to the largest elements.
 */
bool roaring_iterate(const roaring_bitmap_t *r, roaring_iterator iterator,
                     void *ptr);

/**
 * Like `roaring_iterate`, but the 32-bit values are widened to 64 bits by
 * adding `high_bits` (shifted into the upper 32 bits) before being passed to
 * the iterator. This is used to build 64-bit iteration on top of 32-bit
 * bitmaps. `ptr` (can be NULL) is forwarded as the second argument of each
 * call.
 *
 * Returns true if the iterator returned true throughout (so that all values
 * were necessarily visited).
 */
bool roaring_iterate64(const roaring_bitmap_t *r, roaring_iterator64 iterator,
                       uint64_t high_bits, void *ptr);

/**
 * Return true if the two bitmaps contain the same elements.
 */
bool roaring_bitmap_equals(const roaring_bitmap_t *r1,
                           const roaring_bitmap_t *r2);

/**
 * Return true if all the elements of r1 are also in r2.
 */
bool roaring_bitmap_is_subset(const roaring_bitmap_t *r1,
                              const roaring_bitmap_t *r2);

/**
 * Return true if all the elements of r1 are also in r2, and r2 is strictly
 * greater than r1.
 */
bool roaring_bitmap_is_strict_subset(const roaring_bitmap_t *r1,
                                     const roaring_bitmap_t *r2);

/**
 * (For expert users who seek high performance.)
 *
 * Computes the union between two bitmaps and returns new bitmap. The caller is
 * responsible for memory management.
 *
 * The lazy version defers some computations such as the maintenance of the
 * cardinality counts. Thus you must call `roaring_bitmap_repair_after_lazy()`
 * after executing "lazy" computations.
 *
 * It is safe to repeatedly call roaring_bitmap_lazy_or_inplace on the result.
 *
 * `bitsetconversion` is a flag which determines whether container-container
 * operations force a bitset conversion.
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_lazy_or(const roaring_bitmap_t *r1,
                                         const roaring_bitmap_t *r2,
                                         const bool bitsetconversion);

/**
 * (For expert users who seek high performance.)
 *
 * Inplace version of roaring_bitmap_lazy_or, modifies r1.
 *
 * `bitsetconversion` is a flag which determines whether container-container
 * operations force a bitset conversion.
 */
void roaring_bitmap_lazy_or_inplace(roaring_bitmap_t *r1,
                                    const roaring_bitmap_t *r2,
                                    const bool bitsetconversion);

/**
 * (For expert users who seek high performance.)
 *
 * Execute maintenance on a bitmap created from `roaring_bitmap_lazy_or()`
 * or modified with `roaring_bitmap_lazy_or_inplace()`.
 */
void roaring_bitmap_repair_after_lazy(roaring_bitmap_t *r1);

/**
 * Computes the symmetric difference between two bitmaps and returns new bitmap.
 * The caller is responsible for memory management.
 *
 * The lazy version defers some computations such as the maintenance of the
 * cardinality counts. Thus you must call `roaring_bitmap_repair_after_lazy()`
 * after executing "lazy" computations.
 *
 * It is safe to repeatedly call `roaring_bitmap_lazy_xor_inplace()` on
 * the result.
 *
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_lazy_xor(const roaring_bitmap_t *r1,
                                          const roaring_bitmap_t *r2);

/**
 * (For expert users who seek high performance.)
 *
 * Inplace version of roaring_bitmap_lazy_xor, modifies r1. r1 != r2
 */
void roaring_bitmap_lazy_xor_inplace(roaring_bitmap_t *r1,
                                     const roaring_bitmap_t *r2);

/**
 * Compute the negation of the bitmap in the interval [range_start, range_end).
 * The number of negated values is range_end - range_start.
 * Areas outside the range are passed through unchanged.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_flip(const roaring_bitmap_t *r1,
                                      uint64_t range_start, uint64_t range_end);

/**
 * Compute the negation of the bitmap in the interval [range_start, range_end].
 * The number of negated values is range_end - range_start + 1.
 * Areas outside the range are passed through unchanged.
 * The returned pointer may be NULL in case of errors.
 */
roaring_bitmap_t *roaring_bitmap_flip_closed(const roaring_bitmap_t *x1,
                                             uint32_t range_start,
                                             uint32_t range_end);
/**
 * compute (in place) the negation of the roaring bitmap within a specified
 * interval: [range_start, range_end). The number of negated values is
 * range_end - range_start.
 * Areas outside the range are passed through unchanged.
 */
void roaring_bitmap_flip_inplace(roaring_bitmap_t *r1, uint64_t range_start,
                                 uint64_t range_end);

/**
 * compute (in place) the negation of the roaring bitmap within a specified
 * interval: [range_start, range_end]. The number of negated values is
 * range_end - range_start + 1.
 * Areas outside the range are passed through unchanged.
 */
void roaring_bitmap_flip_inplace_closed(roaring_bitmap_t *r1,
                                        uint32_t range_start,
                                        uint32_t range_end);

/**
 * Selects the element at index 'rank' where the smallest element is at index 0.
 * If the size of the roaring bitmap is strictly greater than rank, then this
 * function returns true and sets element to the element of given rank.
 * Otherwise, it returns false.
 */
bool roaring_bitmap_select(const roaring_bitmap_t *r, uint32_t rank,
                           uint32_t *element);

/**
 * roaring_bitmap_rank returns the number of integers that are smaller or equal
 * to x. Thus if x is the first element, this function will return 1. If
 * x is smaller than the smallest element, this function will return 0.
 *
 * The indexing convention differs between roaring_bitmap_select and
 * roaring_bitmap_rank: roaring_bitmap_select refers to the smallest value
 * as having index 0, whereas roaring_bitmap_rank returns 1 when ranking
 * the smallest value.
 */
uint64_t roaring_bitmap_rank(const roaring_bitmap_t *r, uint32_t x);

/**
 * roaring_bitmap_rank_many is an `Bulk` version of `roaring_bitmap_rank`
 * it puts rank value of each element in `[begin .. end)` to `ans[]`
 *
 * the values in `[begin .. end)` must be sorted in Ascending order;
 * Caller is responsible to ensure that there is enough memory allocated, e.g.
 *
 *     ans = malloc((end-begin) * sizeof(uint64_t));
 */
void roaring_bitmap_rank_many(const roaring_bitmap_t *r, const uint32_t *begin,
                              const uint32_t *end, uint64_t *ans);

/**
 * Returns the index of x in the given roaring bitmap.
 * If the roaring bitmap doesn't contain x , this function will return -1.
 * The difference with rank function is that this function will return -1 when x
 * is not the element of roaring bitmap, but the rank function will return a
 * non-negative number.
 */
int64_t roaring_bitmap_get_index(const roaring_bitmap_t *r, uint32_t x);

/**
 * Returns the smallest value in the set, or UINT32_MAX if the set is empty.
 */
uint32_t roaring_bitmap_minimum(const roaring_bitmap_t *r);

/**
 * Returns the greatest value in the set, or 0 if the set is empty.
 */
uint32_t roaring_bitmap_maximum(const roaring_bitmap_t *r);

/**
 * (For advanced users.)
 *
 * Collect statistics about the bitmap, see roaring_types.h for
 * a description of roaring_statistics_t
 */
void roaring_bitmap_statistics(const roaring_bitmap_t *r,
                               roaring_statistics_t *stat);

/**
 * Perform internal consistency checks. Returns true if the bitmap is
 * consistent. It may be useful to call this after deserializing bitmaps from
 * untrusted sources. If roaring_bitmap_internal_validate returns true, then the
 * bitmap should be consistent and can be trusted not to cause crashes or memory
 * corruption.
 *
 * Note that some operations intentionally leave bitmaps in an inconsistent
 * state temporarily, for example, `roaring_bitmap_lazy_*` functions, until
 * `roaring_bitmap_repair_after_lazy` is called.
 *
 * If reason is non-null, it will be set to a string describing the first
 * inconsistency found if any.
 */
bool roaring_bitmap_internal_validate(const roaring_bitmap_t *r,
                                      const char **reason);

/*********************
* What follows is code use to iterate through values in a roaring bitmap

roaring_bitmap_t *r =...
roaring_uint32_iterator_t i;
roaring_iterator_create(r, &i);
while(i.has_value) {
  printf("value = %d\n", i.current_value);
  roaring_uint32_iterator_advance(&i);
}
roaring_uint32_iterator_free(&i);

Obviously, if you modify the underlying bitmap, the iterator
becomes invalid. So don't.
*/

/**
 * A struct used to keep iterator state. Users should only access
 * `current_value` and `has_value`, the rest of the type should be treated as
 * opaque.
 */
typedef struct roaring_uint32_iterator_s {
    const roaring_bitmap_t *parent;        // Owner
    const ROARING_CONTAINER_T *container;  // Current container
    uint8_t typecode;                      // Typecode of current container
    int32_t container_index;               // Current container index
    uint32_t highbits;                     // High 16 bits of the current value
    roaring_container_iterator_t container_it;

    uint32_t current_value;
    bool has_value;
} roaring_uint32_iterator_t;

/**
 * Initialize an iterator object that can be used to iterate through the values.
 * If there is a  value, then this iterator points to the first value and
 * `it->has_value` is true. The value is in `it->current_value`.
 */
void roaring_iterator_init(const roaring_bitmap_t *r,
                           roaring_uint32_iterator_t *newit);

/** DEPRECATED, use `roaring_iterator_init`. */
CROARING_DEPRECATED static inline void roaring_init_iterator(
    const roaring_bitmap_t *r, roaring_uint32_iterator_t *newit) {
    roaring_iterator_init(r, newit);
}

/**
 * Initialize an iterator object that can be used to iterate through the values.
 * If there is a value, then this iterator points to the last value and
 * `it->has_value` is true. The value is in `it->current_value`.
 */
void roaring_iterator_init_last(const roaring_bitmap_t *r,
                                roaring_uint32_iterator_t *newit);

/** DEPRECATED, use `roaring_iterator_init_last`. */
CROARING_DEPRECATED static inline void roaring_init_iterator_last(
    const roaring_bitmap_t *r, roaring_uint32_iterator_t *newit) {
    roaring_iterator_init_last(r, newit);
}

/**
 * Create an iterator object that can be used to iterate through the values.
 * Caller is responsible for calling `roaring_uint32_iterator_free()`.
 *
 * The iterator is initialized (this function calls `roaring_iterator_init()`)
 * If there is a value, then this iterator points to the first value and
 * `it->has_value` is true.  The value is in `it->current_value`.
 */
roaring_uint32_iterator_t *roaring_iterator_create(const roaring_bitmap_t *r);

/** DEPRECATED, use `roaring_iterator_create`. */
CROARING_DEPRECATED static inline roaring_uint32_iterator_t *
roaring_create_iterator(const roaring_bitmap_t *r) {
    return roaring_iterator_create(r);
}

/**
 * Advance the iterator. If there is a new value, then `it->has_value` is true.
 * The new value is in `it->current_value`. Values are traversed in increasing
 * orders. For convenience, returns `it->has_value`.
 *
 * Once `it->has_value` is false, `roaring_uint32_iterator_advance` should not
 * be called on the iterator again. Calling `roaring_uint32_iterator_previous`
 * is allowed.
 */
bool roaring_uint32_iterator_advance(roaring_uint32_iterator_t *it);

/** DEPRECATED, use `roaring_uint32_iterator_advance`. */
CROARING_DEPRECATED static inline bool roaring_advance_uint32_iterator(
    roaring_uint32_iterator_t *it) {
    return roaring_uint32_iterator_advance(it);
}

/**
 * Decrement the iterator. If there's a new value, then `it->has_value` is true.
 * The new value is in `it->current_value`. Values are traversed in decreasing
 * order. For convenience, returns `it->has_value`.
 *
 * Once `it->has_value` is false, `roaring_uint32_iterator_previous` should not
 * be called on the iterator again. Calling `roaring_uint32_iterator_advance` is
 * allowed.
 */
bool roaring_uint32_iterator_previous(roaring_uint32_iterator_t *it);

/** DEPRECATED, use `roaring_uint32_iterator_previous`. */
CROARING_DEPRECATED static inline bool roaring_previous_uint32_iterator(
    roaring_uint32_iterator_t *it) {
    return roaring_uint32_iterator_previous(it);
}

/**
 * Move the iterator to the first value >= `val`. If there is a such a value,
 * then `it->has_value` is true. The new value is in `it->current_value`.
 * For convenience, returns `it->has_value`.
 */
bool roaring_uint32_iterator_move_equalorlarger(roaring_uint32_iterator_t *it,
                                                uint32_t val);

/** DEPRECATED, use `roaring_uint32_iterator_move_equalorlarger`. */
CROARING_DEPRECATED static inline bool
roaring_move_uint32_iterator_equalorlarger(roaring_uint32_iterator_t *it,
                                           uint32_t val) {
    return roaring_uint32_iterator_move_equalorlarger(it, val);
}

/**
 * Creates a copy of an iterator.
 * Caller must free it.
 */
roaring_uint32_iterator_t *roaring_uint32_iterator_copy(
    const roaring_uint32_iterator_t *it);

/** DEPRECATED, use `roaring_uint32_iterator_copy`. */
CROARING_DEPRECATED static inline roaring_uint32_iterator_t *
roaring_copy_uint32_iterator(const roaring_uint32_iterator_t *it) {
    return roaring_uint32_iterator_copy(it);
}

/**
 * Free memory following `roaring_iterator_create()`
 */
void roaring_uint32_iterator_free(roaring_uint32_iterator_t *it);

/** DEPRECATED, use `roaring_uint32_iterator_free`. */
CROARING_DEPRECATED static inline void roaring_free_uint32_iterator(
    roaring_uint32_iterator_t *it) {
    roaring_uint32_iterator_free(it);
}

/**
 * Reads next ${count} values from iterator into user-supplied ${buf}.
 * Returns the number of read elements.
 * This number can be smaller than ${count}, which means that iterator is
 * drained.
 *
 * This function satisfies semantics of iteration and can be used together with
 * other iterator functions.
 *  - first value is copied from ${it}->current_value
 *  - after function returns, iterator is positioned at the next element
 */
uint32_t roaring_uint32_iterator_read(roaring_uint32_iterator_t *it,
                                      uint32_t *buf, uint32_t count);

/** DEPRECATED, use `roaring_uint32_iterator_read`. */
CROARING_DEPRECATED static inline uint32_t roaring_read_uint32_iterator(
    roaring_uint32_iterator_t *it, uint32_t *buf, uint32_t count) {
    return roaring_uint32_iterator_read(it, buf, count);
}

/**
 * Reads previous ${count} values from iterator into user-supplied ${buf}.
 * Returns the number of read elements.
 * This number can be smaller than ${count}, which means that iterator is
 * drained.
 *
 * Values are written in descending order: buf[0] is the highest (current)
 * value, buf[ret-1] is the lowest value read.
 *
 * This function satisfies semantics of reverse iteration and can be used
 * together with other iterator functions.
 *  - first value is copied from ${it}->current_value
 *  - after function returns, iterator is positioned at the previous element
 */
uint32_t roaring_uint32_iterator_read_backward(roaring_uint32_iterator_t *it,
                                               uint32_t *buf, uint32_t count);

/**
 * Skip the next ${count} values from iterator.
 * Returns the number of values actually skipped.
 * The number can be smaller than ${count}, which means that iterator is
 * drained.
 *
 * This function is equivalent to calling `roaring_uint32_iterator_advance()`
 * ${count} times but is much more efficient.
 */
uint32_t roaring_uint32_iterator_skip(roaring_uint32_iterator_t *it,
                                      uint32_t count);

/**
 * Skip the previous ${count} values from iterator (move backwards).
 * Returns the number of values actually skipped backwards.
 * The number can be smaller than ${count}, which means that iterator reached
 * the beginning.
 *
 * This function is equivalent to calling `roaring_uint32_iterator_previous()`
 * ${count} times but is much more efficient.
 */
uint32_t roaring_uint32_iterator_skip_backward(roaring_uint32_iterator_t *it,
                                               uint32_t count);

typedef struct roaring_uint32_range_closed_s {
    uint32_t min;
    uint32_t max;
} roaring_uint32_range_closed_t;

/**
 * Reads next ${count} ranges from iterator into user-supplied ${buf}.
 * A range is defined as a maximal interval of consecutive values.
 * For example, the set {1,2,3,5,6} contains two ranges: [1..3] and [5..6].
 * Each range is represented as a struct {min,max}, both endpoints included.
 * Consecutive values that span internal container boundaries are merged into
 * a single range.
 *
 * Returns the number of read ranges.
 * This number can be smaller than ${count}, which means that the iterator is
 * drained.
 *
 * This function satisfies the semantics of iteration and can be used together
 * with other iterator functions.
 *  - first range will start with ${it}->current_value
 *  - after the function returns, the iterator is positioned at the next element
 *    after the end of the last returned range, or ${it}->has_value is false if
 *    the bitmap is exhausted.
 */
size_t roaring_uint32_iterator_read_ranges(roaring_uint32_iterator_t *it,
                                           roaring_uint32_range_closed_t *buf,
                                           size_t count);

/**
 * Reads previous ${count} ranges from iterator into user-supplied ${buf}.
 * A range is defined as a maximal interval of consecutive values.
 * For example, the set {1,2,3,5,6} contains two ranges: [1..3] and [5..6].
 * Each range is represented as a struct {min,max}, both endpoints included.
 * Consecutive values that span internal container boundaries are merged into
 * a single range.
 *
 * Returns the number of read ranges.
 * This number can be smaller than ${count}, which means that the iterator is
 * drained.
 *
 * Ranges are returned in reverse order, e.g. the first range returned is the
 * highest range (ending at the current value)
 *
 * This function satisfies the semantics of reverse iteration and can be used
 * together with other iterator functions.
 *  - first range will end with ${it}->current_value
 *  - after the function returns, the iterator is positioned at the element
 *    before the beginning of the last returned range, or ${it}->has_value is
 *    false if the bitmap is exhausted.
 */
size_t roaring_uint32_iterator_read_prev_ranges(
    roaring_uint32_iterator_t *it, roaring_uint32_range_closed_t *buf,
    size_t count);

#ifdef __cplusplus
}
}
}  // extern "C" { namespace roaring { namespace api {
#endif

#endif /* ROARING_H */

#ifdef __cplusplus
/**
 * Best practices for C++ headers is to avoid polluting global scope.
 * But for C compatibility when just `roaring.h` is included building as
 * C++, default to global access for the C public API.
 *
 * BUT when `roaring.hh` is included instead, it sets this flag.  That way
 * explicit namespacing must be used to get the C functions.
 *
 * This is outside the include guard so that if you include BOTH headers,
 * the order won't matter; you still get the global definitions.
 */
#if !defined(ROARING_API_NOT_IN_GLOBAL_NAMESPACE)
using namespace ::roaring::api;
#endif
#endif

// roaring64 will include roaring.h, but we would
// prefer to avoid having our users include roaring64.h
// in addition to roaring.h.
#include <roaring/roaring64.h>

Coverage Report

Created: 2026-10-17 07:19