c2bc99ad9b
I made a few modifications to the database, and introduced an "IndexEntry" database type to do the exact same thing :) Signed-off-by: Anna Schumaker <schumaker.anna@gmail.com>
53 lines
1.7 KiB
Plaintext
53 lines
1.7 KiB
Plaintext
== Files ==
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ocarina/include/
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filter.h
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ocarina/lib/
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filter.cpp
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== Depends ==
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database
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Filter: (lib/filter.cpp)
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Filtering is used to generate a subset of songs displayed by the UI to
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that users can choose from. The inverted index is generated at startup
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so there is no need for a remove() function, since it will be wiped
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the next time the application starts.
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- Index:
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Database<database :: IndexEntry> filter_index;
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map<string, string> lowercase_cache;
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unsigned int lowercase_cache_hits;
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- Parsing:
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1) Convert the provided string into a list of words, using whitespace
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and the following characters as delimiters: \/,;()_-~+"
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For each word:
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2) Check the lowercase_cache to see if we have seen the word before,
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a) If we have, return the stored string
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b) Convert the string to lowercase and strip out remaining
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special characters. Add the result to the lowercase_cache;
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- API:
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void filter :: add(string, track_id);
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Parse the string into substrings following the "Parsing"
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section (above). Add each (substring, track_id) pair to the
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filter_index.
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To generate substrings, iterate over the word starting from
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the front. For example: "dalek" would contain the substrings
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{d, da, dal, dale, dalek}.
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void filter :: search(string, set<track_id> &);
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Parse the string into substrings following the "Parsing"
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section (above). We want to find track_ids that match ALL
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substrings, so take the intersection of all sets returned by
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the filter_index for a given substring.
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void filter :: print_cache_stats();
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Print cache hit and size information.
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void filter :: get_index();
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Return the index storing all the filter data.
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(Only available if -DCONFIG_TEST is set)
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