Function GenerateTermsForPath

pg_documentdb/src/opclass/bson_gin_core.c:1100–1164

void
GenerateTermsForPath(pgbson *bson, GenerateTermsContext *context)
{
	bson_iter_t bsonIterator;
	Assert(context->pathDataState != NULL);
	Assert(context->getPathDataFunc != NULL);

	/* now walk the entries and insert the terms */
	PgbsonInitIterator(bson, &bsonIterator);

	/* Initialize with minimum capacity */
	/* provision 1 root term + 1 value term/not-found term */
	for (int i = 0; i < context->maxPaths; i++)
	{
		GinEntryPathData *pathData = context->getPathDataFunc(context->pathDataState, i);

		pathData->terms.entries = palloc0(sizeof(Datum) * 2);
		pathData->terms.entryCapacity = 2;
		pathData->terms.index = 0;
		pathData->coreTermsCount = 0;
		pathData->hasTruncatedTerms = false;
		pathData->hasArrayAncestors = false;
		pathData->hasArrayValues = false;
	}

	bool inArrayContext = false;
	bool isArrayTerm = false;
	bool isCheckForArrayTermsWithNestedDocument = false;
	GenerateTermsCore(&bsonIterator, "", 0, inArrayContext,
					  isArrayTerm, context,
					  isCheckForArrayTermsWithNestedDocument);


	for (int i = 0; i < context->maxPaths; i++)
	{
		GinEntryPathData *pathData = context->getPathDataFunc(context->pathDataState, i);
		pathData->coreTermsCount = pathData->terms.index;
		bool hasNoTerms = pathData->coreTermsCount == 0;

		/* Add the path not found term if necessary
		 * we do this for back compat only when the index used the legacy not found term
		 */
		if (hasNoTerms && context->generateNotFoundTerm)
		{
			AddTerm(&pathData->terms, GeneratePathUndefinedTerm(context->options));
		}

		if (pathData->generatePathBasedUndefinedTerms)
		{
			if (hasNoTerms)
			{
				/* Add the path not exists value term */
				AddTerm(&pathData->terms, GenerateValueUndefinedTerm(
							&pathData->termMetadata));
			}

			if (pathData->hasArrayPartialTermExistence)
			{