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/* 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;
}
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