Function GenerateTerms

pg_documentdb/src/opclass/bson_gin_core.c:1173–1216

* This is the core logic that walks through a document and generates terms. * The generation happens in 2 phases: first to compute the total number of terms * and space to allocate, and the second to walk the structure and actually generate * the terms necessary. */

 * the terms necessary.
 */
void
GenerateTerms(pgbson *bson, GenerateTermsContext *context, GinEntryPathData *pathData,
			  bool addRootTerm)
{
	context->pathDataState = pathData;
	context->getPathDataFunc = GetPathDataDefault;
	context->isRecursivePathMatch = IsRecursivePathMatch;
	context->currentRecursivePathIndex = GetCurrentRecursivePaths;
	context->maxPaths = 1;

	GenerateTermsForPath(bson, context);
	bool hasTerms = pathData->coreTermsCount > 0;
	if (addRootTerm)
	{
		/* GUC to preserve back-compat behavior. */
		if (!EnableGenerateNonExistsTerm)
		{
			AddTerm(&pathData->terms, GenerateRootTerm(
						&pathData->termMetadata));
		}
		else if (hasTerms)
		{
			AddTerm(&pathData->terms, GenerateRootExistsTerm(
						&pathData->termMetadata));
		}
		else
		{
			AddTerm(&pathData->terms, GenerateRootNonExistsTerm(
						&pathData->termMetadata));
		}

		if (pathData->hasTruncatedTerms)
		{
			AddTerm(&pathData->terms, GenerateRootTruncatedTerm(
						&pathData->termMetadata));
		}

		if (pathData->hasArrayAncestors)
		{
			AddTerm(&pathData->terms, GenerateRootMultiKeyTerm(
						&pathData->termMetadata));
		}
	}
}


static void