67 lines
1.7 KiB
C++
67 lines
1.7 KiB
C++
#include <hilbert/kernel/storage.hpp>
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namespace hilbert::kernel::storage {
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bd_result block_device::load_cache_block(uint64_t i) {
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if (block_cache_i == i)
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return bd_result::success;
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bd_result result = read_blocks_no_cache(i, 1, block_cache);
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if (result != bd_result::success) {
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block_cache_i = block_count;
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return result;
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}
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block_cache_i = i;
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return bd_result::success;
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}
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bd_result block_device::read_bytes(
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uint64_t start, uint64_t count, void *into
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) {
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if (start + count > block_size * block_count)
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return bd_result::out_of_bounds;
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uint8_t *into_u8 = (uint8_t *)into;
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if (start % block_size != 0) {
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uint64_t prefix_len = block_size - start % block_size;
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bd_result result = load_cache_block(start / block_size);
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if (result != bd_result::success)
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return result;
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for (uint64_t i = 0; i < prefix_len; ++i)
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into_u8[i] = block_cache[start % block_size + i];
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into_u8 += prefix_len;
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start += prefix_len;
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count -= prefix_len;
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}
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uint64_t postfix_start = ((start + count) / block_size) * block_size;
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if (postfix_start != start) {
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bd_result result = read_blocks_no_cache(
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start / block_size, (postfix_start - start) / block_size, into_u8);
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if (result != bd_result::success)
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return result;
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count -= postfix_start - start;
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into_u8 += postfix_start - start;
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start = postfix_start;
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}
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if (count != 0) {
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bd_result result = load_cache_block(start / block_size);
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if (result != bd_result::success)
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return result;
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for (uint64_t i = 0; i < count; ++i)
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into_u8[i] = block_cache[i];
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}
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return bd_result::success;
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}
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}
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