ulib/bitmap/rle-bitmap.cpp

43 zx_status_t RleBitmap::Find(bool is_set, size_t bitoff, size_t bitmax, size_t run_len, size_t* out)
45     *out = bitmax;
50     // Therefore, we can check whether |run_len| bits between |bitmax| and |bitoff| exist before
55         } else if (bitmax - bitoff < run_len) {
60         size_t elem_max = fbl::min(bitmax, elem.end()); // Maximum valid bit within elem.
64             // which are between |bitoff| and |bitmax|.
75         if (bitmax < elem.end()) {
86     if (!is_set && bitmax - bitoff >= run_len) {
97 bool RleBitmap::Get(size_t bitoff, size_t bitmax, size_t* first_unset) const {
107     if (bitoff > bitmax) {
108         bitoff = bitmax;
114     return bitoff == bitmax;
123 zx_status_t RleBitmap::Set(size_t bitoff, size_t bitmax) {
124     return SetInternal(bitoff, bitmax, nullptr);
127 zx_status_t RleBitmap::SetNoAlloc(size_t bitoff, size_t bitmax, FreeList* free_list) {
132     return SetInternal(bitoff, bitmax, free_list);
135 zx_status_t RleBitmap::Clear(size_t bitoff, size_t bitmax) {
136     return ClearInternal(bitoff, bitmax, nullptr);
139 zx_status_t RleBitmap::ClearNoAlloc(size_t bitoff, size_t bitmax, FreeList* free_list) {
144     return ClearInternal(bitoff, bitmax, free_list);
147 zx_status_t RleBitmap::SetInternal(size_t bitoff, size_t bitmax, FreeList* free_list) {
148     if (bitmax < bitoff) {
152     const size_t bitlen = bitmax - bitoff;
210 zx_status_t RleBitmap::ClearInternal(size_t bitoff, size_t bitmax, FreeList* free_list) {
211     if (bitmax < bitoff) {
215     if (bitmax - bitoff == 0) {
225         if (bitmax < itr->bitoff) {
229             if (itr->bitoff + itr->bitlen <= bitmax) {
236                 // '*itr' contains [bitoff, bitmax), and we need to split it.
242                 new_elem->bitoff = bitmax;
243                 new_elem->bitlen = itr->bitoff + itr->bitlen - bitmax;
247                 num_bits_ -= (bitmax - bitoff);
251             if (bitmax < itr->bitoff + itr->bitlen) {
252                 // 'elem' contains 'bitmax'
253                 num_bits_ -= (bitmax - itr->bitoff);
254                 itr->bitlen = itr->bitoff + itr->bitlen - bitmax;
255                 itr->bitoff = bitmax;
258                 // [bitoff, bitmax) fully contains '*itr'.