update,

mercury25/task1/provided/rbuoy_provided.c

@@ -0,0 +1,47 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <assert.h>
+
+#include "rbuoy.h"
+
+
+/// @brief Compute the hash of a block of bytes, using the 64 bit NFV-1a hash.
+///
+/// If you wish to represent your bytes differently (say as an array of uint8_t)
+/// you may want to make a wrapper around this function.
+///
+/// @param block      The array of bytes to be hashed.
+/// @param block_size The length of that array. Must be at most 256.
+///
+/// @return The hash of the block.
+uint64_t hash_block(char block[], size_t block_size) {
+    assert(block_size <= BLOCK_SIZE);
+
+    uint64_t hash = 0xcbf29ce484222325ull;
+    for (size_t i = 0; i < block_size; ++i) {
+        hash ^= (unsigned char) block[i];
+        hash *= 0x100000001b3;
+    }
+
+    return hash;
+}
+
+
+/// @brief Compute the number of blocks in a file, given its size.
+/// @param num_bytes The number of bytes in a file.
+/// @return The nunber of blocks that are needed for that file.
+size_t number_of_blocks_in_file(size_t num_bytes) {
+    // This is equal to
+    //   ceil(num_bytes / BLOCK_SIZE)
+    return (num_bytes + BLOCK_SIZE - 1) / BLOCK_SIZE;
+}
+
+
+/// @brief Compute the nunber of 'match' bytes that are needed for a TBBI record.
+/// @param num_blocks The number of blocks.
+/// @return The number of 'match' bytes needed.
+size_t num_tbbi_match_bytes(size_t num_blocks) {
+    // This is equal to
+    //   ceil(num_blocks / 8)
+    return (num_blocks + MATCH_BYTE_BITS - 1) / MATCH_BYTE_BITS;
+}