26 lines
972 B
TypeScript
26 lines
972 B
TypeScript
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function extractDataFromBlock (block: Uint8Array, blockStart: bigint, requestedStart: bigint, requestedEnd: bigint): Uint8Array {
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const blockLength = BigInt(block.length)
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const blockEnd = BigInt(blockStart + blockLength)
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if (requestedStart >= blockEnd || requestedEnd < blockStart) {
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// If we are looking for a byte range that is starts after the start of the block,
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// return an empty block. This can happen when internal nodes contain data
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return new Uint8Array(0)
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}
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if (requestedEnd >= blockStart && requestedEnd < blockEnd) {
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// If the end byte is in the current block, truncate the block to the end byte
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block = block.subarray(0, Number(requestedEnd - blockStart))
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}
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if (requestedStart >= blockStart && requestedStart < blockEnd) {
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// If the start byte is in the current block, skip to the start byte
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block = block.subarray(Number(requestedStart - blockStart))
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}
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return block
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}
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export default extractDataFromBlock
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