diff options
Diffstat (limited to 'comm/mailnews/extensions/fts3/nsGlodaRankerFunction.cpp')
-rw-r--r-- | comm/mailnews/extensions/fts3/nsGlodaRankerFunction.cpp | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/comm/mailnews/extensions/fts3/nsGlodaRankerFunction.cpp b/comm/mailnews/extensions/fts3/nsGlodaRankerFunction.cpp new file mode 100644 index 0000000000..9ba125466f --- /dev/null +++ b/comm/mailnews/extensions/fts3/nsGlodaRankerFunction.cpp @@ -0,0 +1,106 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsGlodaRankerFunction.h" +#include "mozIStorageValueArray.h" + +#include "sqlite3.h" + +#include "nsCOMPtr.h" +#include "nsVariant.h" +#include "nsComponentManagerUtils.h" + +#ifndef SQLITE_VERSION_NUMBER +# error "We need SQLITE_VERSION_NUMBER defined!" +#endif + +NS_IMPL_ISUPPORTS(nsGlodaRankerFunction, mozIStorageFunction) + +nsGlodaRankerFunction::nsGlodaRankerFunction() {} + +nsGlodaRankerFunction::~nsGlodaRankerFunction() {} + +static uint32_t COLUMN_SATURATION[] = {10, 1, 1, 1, 1}; + +/** + * Our ranking function basically just multiplies the weight of the column + * against the number of (saturating) matches. + * + * The original code is a SQLite example ranking function, although somewhat + * rather modified at this point. All SQLite code is public domain, so we are + * subsuming it to MPL1.1/LGPL2/GPL2. + */ +NS_IMETHODIMP +nsGlodaRankerFunction::OnFunctionCall(mozIStorageValueArray* aArguments, + nsIVariant** _result) { + // all argument names are maintained from the original SQLite code. + uint32_t nVal; + nsresult rv = aArguments->GetNumEntries(&nVal); + NS_ENSURE_SUCCESS(rv, rv); + + /* Check that the number of arguments passed to this function is correct. + * If not, return an error. Set aArgsData to point to the array + * of unsigned integer values returned by FTS3 function. Set nPhrase + * to contain the number of reportable phrases in the users full-text + * query, and nCol to the number of columns in the table. + */ + if (nVal < 1) return NS_ERROR_INVALID_ARG; + + uint32_t lenArgsData; + uint32_t* aArgsData = (uint32_t*)aArguments->AsSharedBlob(0, &lenArgsData); + + uint32_t nPhrase = aArgsData[0]; + uint32_t nCol = aArgsData[1]; + if (nVal != (1 + nCol)) return NS_ERROR_INVALID_ARG; + + double score = 0.0; + + // SQLite 3.6.22 has a different matchinfo layout than SQLite 3.6.23+ +#if SQLITE_VERSION_NUMBER <= 3006022 + /* Iterate through each phrase in the users query. */ + for (uint32_t iPhrase = 0; iPhrase < nPhrase; iPhrase++) { + // in SQ + for (uint32_t iCol = 0; iCol < nCol; iCol++) { + uint32_t nHitCount = aArgsData[2 + (iPhrase + 1) * nCol + iCol]; + double weight = aArguments->AsDouble(iCol + 1); + if (nHitCount > 0) { + score += (nHitCount > COLUMN_SATURATION[iCol]) + ? (COLUMN_SATURATION[iCol] * weight) + : (nHitCount * weight); + } + } + } +#else + /* Iterate through each phrase in the users query. */ + for (uint32_t iPhrase = 0; iPhrase < nPhrase; iPhrase++) { + /* Now iterate through each column in the users query. For each column, + ** increment the relevancy score by: + ** + ** (<hit count> / <global hit count>) * <column weight> + ** + ** aPhraseinfo[] points to the start of the data for phrase iPhrase. So + ** the hit count and global hit counts for each column are found in + ** aPhraseinfo[iCol*3] and aPhraseinfo[iCol*3+1], respectively. + */ + uint32_t* aPhraseinfo = &aArgsData[2 + iPhrase * nCol * 3]; + for (uint32_t iCol = 0; iCol < nCol; iCol++) { + uint32_t nHitCount = aPhraseinfo[3 * iCol]; + double weight = aArguments->AsDouble(iCol + 1); + if (nHitCount > 0) { + score += (nHitCount > COLUMN_SATURATION[iCol]) + ? (COLUMN_SATURATION[iCol] * weight) + : (nHitCount * weight); + } + } + } +#endif + + nsCOMPtr<nsIWritableVariant> result = new nsVariant(); + + rv = result->SetAsDouble(score); + NS_ENSURE_SUCCESS(rv, rv); + + result.forget(_result); + return NS_OK; +} |