diff options
Diffstat (limited to 'src/cuckoocache.h')
| -rw-r--r-- | src/cuckoocache.h | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/src/cuckoocache.h b/src/cuckoocache.h index d0dc61c7e6..61f553806e 100644 --- a/src/cuckoocache.h +++ b/src/cuckoocache.h @@ -12,7 +12,9 @@ #include <atomic> #include <cmath> #include <cstring> +#include <limits> #include <memory> +#include <optional> #include <utility> #include <vector> @@ -326,7 +328,7 @@ public: } /** setup initializes the container to store no more than new_size - * elements. + * elements and no less than 2 elements. * * setup should only be called once. * @@ -336,8 +338,8 @@ public: uint32_t setup(uint32_t new_size) { // depth_limit must be at least one otherwise errors can occur. - depth_limit = static_cast<uint8_t>(std::log2(static_cast<float>(std::max((uint32_t)2, new_size)))); size = std::max<uint32_t>(2, new_size); + depth_limit = static_cast<uint8_t>(std::log2(static_cast<float>(size))); table.resize(size); collection_flags.setup(size); epoch_flags.resize(size); @@ -357,12 +359,21 @@ public: * * @param bytes the approximate number of bytes to use for this data * structure - * @returns the maximum number of elements storable (see setup() - * documentation for more detail) + * @returns A pair of the maximum number of elements storable (see setup() + * documentation for more detail) and the approxmiate total size of these + * elements in bytes or std::nullopt if the size requested is too large. */ - uint32_t setup_bytes(size_t bytes) + std::optional<std::pair<uint32_t, size_t>> setup_bytes(size_t bytes) { - return setup(bytes/sizeof(Element)); + size_t requested_num_elems = bytes / sizeof(Element); + if (std::numeric_limits<uint32_t>::max() < requested_num_elems) { + return std::nullopt; + } + + auto num_elems = setup(bytes/sizeof(Element)); + + size_t approx_size_bytes = num_elems * sizeof(Element); + return std::make_pair(num_elems, approx_size_bytes); } /** insert loops at most depth_limit times trying to insert a hash |