PROTON-2178 Implement efficient search of encoded Symbol on ReadableBuffer #36
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…uffer The search algorithm chosen is Knuth-Morris-Pratt and could make use of an additional jump table with certain Symbols
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Some benchmark results are on netty/netty#9955 |
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I see that I'm not accounting for remaining space to search in to be less then the needle to search for :) |
gemmellr
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gemmellr
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I dont think it really makes sense to add this to the Symbol object itself, since it doesn't actually identify an encoded Symbol in the provided buffer, but rather a sequence of bytes in the buffer that matches its ascii content, but which could be from [part of] absolutely any type or value. Essentially its a general search of the buffer, which seems more suited to being outside the Symbol class if anywhere to me.
| int j = 0; | ||
| final int[] jumpTable = racyGerOrCreateJumpTable(); | ||
| final byte[] needle = _underlyingBytes; | ||
| final long length = to - from; |
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Given the other checking above, should it perhaps also validate that to <= from?
| throw new IllegalArgumentException("range indexes cannot be negative!"); | ||
| } | ||
| int j = 0; | ||
| final int[] jumpTable = racyGerOrCreateJumpTable(); |
| final int[] jumpTable = racyGerOrCreateJumpTable(); | ||
| final byte[] needle = _underlyingBytes; | ||
| final long length = to - from; | ||
| final ReadableBuffer haystack = buffer; |
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Any reason not to just declare the method arg with the desired name + final?
| final long length = to - from; | ||
| final ReadableBuffer haystack = buffer; | ||
| final int needleLength = needle.length; | ||
| for (int i = 0; i < length; i++) |
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Would initialising i to 'from' rather than 0 simplify things? (Plus other adjustments accordingly, e.g rename i to index, to rather than length)
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Hi @gemmellr I can close this and sorry to have made you to review this: I've included this general purpose search method directly on AMQ code base, but still, would be useful (maybe in a new codec) a method to perform a "real" search for a specific property key in some section of AMQP, instead of a greedy approach like this. |
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The search algorithm chosen is Knuth-Morris-Pratt and could make
use of an additional jump table with certain Symbols