• 对CRoaring进行封装的PHP扩展库，兼容 PHP 7.x & PHP 5.6，在 PHP 7.2.16 以及 PHP 5.6.30下测试通过(CentOS 7.6 64-bit)
• githup上的CRoaring
• 文件夹里包含的roaring.h roaring.hh roaring.c是CRoaring的0.2.60版本，用amalgamation.sh生成的。因此编译本库不依赖其他额外的库。
• Roaring bitmap其中一个用途是非常高效的计算DAU以及留存（两个bitmap做and操作即可）等统计，解决PHP保存所有用户ID的原生数组占用过多内存的问题。

• #cd /your/php-src-dir/ext
• git clone https://github.com/paultan63/php-roaring_bitmap-extension.git roaring_bitmap
• cd roaring_bitmap
• phpize
• ./configure
• make install
• #add extension=roaring_bitmap.so to php.ini

• 下载后将本目录改名roaring_bitmap并放进php的源代码目录，譬如php-7.xxx/ext/roaring_bitmap
• 进入这个目录，并且运行phpize && ./configure && make install
• 修改php.ini，将extension=roaring_bitmap.so加进去

• All method accept 32-bit integer only
• If there is no requirement for 64-bit integers, 32-bit roaring_bitmap should be used for better performance.

$roaring = new roaring_bitmap;

$roaring->addMany(array(1,2,3));

$n = 3;
printf("contains %d: %d\n", $n, $roaring->contains($n));

$roaring2 = new roaring_bitmap;
$roaring2->addMany(array(10,11,12));

$roaring->or($roaring2);
printf("cardinality:%u\n", $roaring->cardinality());
$n=10;
printf("contains %d: %d\n", $n, $roaring->contains($n));

printf("roaring2 isSubset:%d\n", $roaring2->isSubSet($roaring));

printf("roaring values:");
for($roaring->iterator_begin(); $roaring->iterator_end() === false; $roaring->iterator_advance()){
        printf("%u,", $roaring->iterator_value());
}
printf("\n");

$vals = $roaring->toArray();
print_r($vals);

All method accept 32 bit or 64 bit integer

$roaring = new roaring_bitmap64;

$roaring->addMany(array(9000000000000000100,9000000000000000101,9000000000000000102));

$n = 9000000000000000102;
printf("contains %d: %d\n", $n, $roaring->contains($n));

$roaring2 = new roaring_bitmap64;
$roaring2->addMany(array(9000000000000000110,9000000000000000111,9000000000000000112));

$roaring->or($roaring2);
printf("cardinality:%u\n", $roaring->cardinality());
$n=10;
printf("contains %d: %d\n", $n, $roaring->contains($n));

printf("roaring2 isSubset:%d\n", $roaring2->isSubSet($roaring));

printf("roaring values:");
for($roaring->iterator_begin(); $roaring->iterator_end() === false; $roaring->iterator_advance()){
        printf("%u,", $roaring->iterator_value());
}
printf("\n");

$vals = $roaring->toArray();
print_r($vals);

• void roaring_bitmap::__construct()

Create the roaring_bitmap object

• long roaring_bitmap::add(long $n)

Add value n

• bool roaring_bitmap::addChecked(long $n)

Add value n. Returns true if a new value was added, false if the value was already existing

• void roaring_bitmap::addRange(long $x, long $y)

add if all values from x (included) to y (excluded)

• long roaring_bitmap::addMany(array $arr)

Add value from array $arr

• long roaring_bitmap::remove(long $n)

Remove value n

• bool roaring_bitmap::removeChecked(long $n)

Remove value n. Returns true if a new value was removed, false if the value was not existing.

• long roaring_bitmap::maximum()

Return the largest value (if not empty)

• long roaring_bitmap::minimum()

Return the smallest value (if not empty)

• bool roaring_bitmap::contains(long $n)

Check if value n is present

• bool roaring_bitmap::contains(long $x, long $y)

Check if all values from x (included) to y (excluded) are present

• long roaring_bitmap::rank(long $n)

Returns the number of integers that are smaller or equal to n.

• long roaring_bitmap::select(long $rank)

If the size of the roaring bitmap is strictly greater than rank, then this function returns the element of given rank. Otherwise, it returns false.

• bool roaring_bitmap::flip(long $begin, long $end)

compute the negation of the roaring bitmap within a specified interval. areas outside the range are passed through unchanged.

• bool roaring_bitmap::isEmpty()

Returns true if the bitmap is empty (cardinality is zero).

• long roaring_bitmap::cardinality()

Get the cardinality of the bitmap (number of elements).

• long roaring_bitmap::getSizeInBytes([bool $portable = false])

How many bytes are required to serialize this bitmap. Setting the portable flag to false enable a custom format that can save space compared to the portable format (e.g., for very sparse bitmaps).

• long roaring_bitmap::replace(roaring_bitmap $another)

Copies the content of the provided bitmap, and discard the current content.

• bool roaring_bitmap::eq(roaring_bitmap $another)

Return true if the two bitmaps contain the same elements.

• long roaring_bitmap::sub(roaring_bitmap $another)

Compute the difference between the current bitmap and the provided bitmap, writing the result in the current bitmap. The provided bitmap is not modified.

• long roaring_bitmap::and(roaring_bitmap $another)

Copies the content of the provided bitmap, and discard the current content.

• long roaring_bitmap::or(roaring_bitmap $another)

Compute the union between the current bitmap and the provided bitmap, writing the result in the current bitmap. The provided bitmap is not modified.

• long roaring_bitmap::xor(roaring_bitmap $another)

Compute the symmetric union between the current bitmap and the provided bitmap, writing the result in the current bitmap. The provided bitmap is not modified.

• long roaring_bitmap::and_cardinality(roaring_bitmap $another)

Computes the size of the intersection between two bitmaps.

• long roaring_bitmap::or_cardinality(roaring_bitmap $another)

Computes the size of the union between two bitmaps.

• long roaring_bitmap::andnot_cardinality(roaring_bitmap $another)

Computes the size of the difference (andnot) between two bitmaps.

• long roaring_bitmap::xor_cardinality(roaring_bitmap $another)

Computes the size of the symmetric difference (andnot) between two bitmaps.

• double roaring_bitmap::jaccard_index(roaring_bitmap $another)

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.

• bool roaring_bitmap::isSubset(roaring_bitmap $another)

Returns true if the bitmap is subset of the other.

• bool roaring_bitmap::isStrictSubset(roaring_bitmap $another)

Returns true if the bitmap is strict subset of the other.

• bool roaring_bitmap::iterator_begin()

Iterate over the bitmap elements. Move the iterator to the first value.

• bool roaring_bitmap::iterator_end()

Return false means that the iteration should continue while true means that it should stop.

• bool roaring_bitmap::iterator_advance()

Move the iterator to the next.

• long roaring_bitmap::iterator_value()

Return current iterator value.

• array roaring_bitmap::toArray()

Convert the bitmap to an array and return it. array size is: this->cardinality()

• string roaring_bitmap::toString()

Print the content of the bitmap into a string and return it.

• string roaring_bitmap::write([bool $portable = false])

write a bitmap to a char buffer. Returns how many bytes were written which should be getSizeInBytes(). Setting the portable flag to false enable a custom format that can save space compared to the portable format (e.g., for very sparse bitmaps).

• bool roaring_bitmap::read(string $data, [bool $portable = false])

read a bitmap from a serialized version. Setting the portable flag to false enable a custom format that can save space compared to the portable format (e.g., for very sparse bitmaps).

• bool roaring_bitmap::getCopyOnWrite()

Whether or not copy and write is active.

• bool roaring_bitmap::setCopyOnWrite()

Whether or not we apply copy and write.

• bool roaring_bitmap::removeRunCompression()

Remove run-length encoding even when it is more space efficient return whether a change was applied.

• bool roaring_bitmap::runOptimize()

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().

• long roaring_bitmap::shrinkToFit()

If needed, reallocate memory to shrink the memory usage. Returns the number of bytes saved.

• void roaring_bitmap64::__construct()

Create the roaring_bitmap64 object

• long roaring_bitmap64::add(string $n)

Add value n(numeric string)

• bool roaring_bitmap64::addChecked(string $n)

Add value n. Returns true if a new value was added, false if the value was already existing

• long roaring_bitmap64::addMany(array $arr)

Add value from array $arr

• long roaring_bitmap64::remove(string $n)

Remove value n

• bool roaring_bitmap64::removeChecked(string $n)

Remove value n. Returns true if a new value was removed, false if the value was not existing.

• string roaring_bitmap64::maximum()

Return the largest value (if not empty)

• string roaring_bitmap64::minimum()

Return the smallest value (if not empty)

• bool roaring_bitmap64::contains(string $n)

Check if value n is present

• string roaring_bitmap64::rank(string $n)

Returns the number of integers that are smaller or equal to n.

• string roaring_bitmap64::select(string $rank)

If the size of the roaring bitmap is strictly greater than rank, then this function returns the element of given rank. Otherwise, it returns false.

• bool roaring_bitmap64::flip(string $begin, string $end)

compute the negation of the roaring bitmap within a specified interval. areas outside the range are passed through unchanged.

• bool roaring_bitmap64::isEmpty()

Returns true if the bitmap is empty (cardinality is zero).

• string roaring_bitmap64::cardinality()

Get the cardinality of the bitmap (number of elements).

• string roaring_bitmap64::getSizeInBytes([bool $portable = false])

How many bytes are required to serialize this bitmap. Setting the portable flag to false enable a custom format that can save space compared to the portable format (e.g., for very sparse bitmaps).

• long roaring_bitmap64::replace(roaring_bitmap64 $another)

Copies the content of the provided bitmap, and discard the current content.

• bool roaring_bitmap64::eq(roaring_bitmap64 $another)

Return true if the two bitmaps contain the same elements.

• long roaring_bitmap64::sub(roaring_bitmap64 $another)

Compute the difference between the current bitmap and the provided bitmap, writing the result in the current bitmap. The provided bitmap is not modified.

• long roaring_bitmap64::and(roaring_bitmap64 $another)

Copies the content of the provided bitmap, and discard the current content.

• long roaring_bitmap64::or(roaring_bitmap64 $another)

Compute the union between the current bitmap and the provided bitmap, writing the result in the current bitmap. The provided bitmap is not modified.

• long roaring_bitmap64::xor(roaring_bitmap64 $another)

Compute the symmetric union between the current bitmap and the provided bitmap, writing the result in the current bitmap. The provided bitmap is not modified.

• bool roaring_bitmap64::isSubset(roaring_bitmap64 $another)

Returns true if the bitmap is subset of the other.

• bool roaring_bitmap64::isStrictSubset(roaring_bitmap64 $another)

Returns true if the bitmap is strict subset of the other.

• bool roaring_bitmap64::iterator_begin()

Iterate over the bitmap elements. Move the iterator to the first value.

• bool roaring_bitmap64::iterator_end()

Return false means that the iteration should continue while true means that it should stop.

• bool roaring_bitmap64::iterator_advance()

Move the iterator to the next.

• string roaring_bitmap64::iterator_value()

Return current iterator value.

• array roaring_bitmap64::toArray()

Convert the bitmap to an array and return it. array size is: this->cardinality()

• string roaring_bitmap64::toString()

Print the content of the bitmap into a string and return it.

• string roaring_bitmap64::write([bool $portable = false])

write a bitmap to a char buffer. Returns how many bytes were written which should be getSizeInBytes(). Setting the portable flag to false enable a custom format that can save space compared to the portable format (e.g., for very sparse bitmaps).

• bool roaring_bitmap64::read(string $data, [bool $portable = false])

read a bitmap from a serialized version. Setting the portable flag to false enable a custom format that can save space compared to the portable format (e.g., for very sparse bitmaps).

• bool roaring_bitmap64::getCopyOnWrite()

Whether or not copy and write is active.

• bool roaring_bitmap64::setCopyOnWrite()

Whether or not we apply copy and write.

• bool roaring_bitmap64::removeRunCompression()

Remove run-length encoding even when it is more space efficient return whether a change was applied.

• bool roaring_bitmap64::runOptimize()

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().

• long roaring_bitmap64::shrinkToFit()

If needed, reallocate memory to shrink the memory usage. Returns the number of bytes saved.