v32-0006-Add-jsonb-support-function-JsonbUnquote.patch

From 1a0b0f64219d01c6cf185b3132afd9b1a64069eb Mon Sep 17 00:00:00 2001
From: Amit Langote <amitlan@postgresql.org>
Date: Thu, 14 Dec 2023 15:12:27 +0900
Subject: [PATCH v32 6/8] Add jsonb support function JsonbUnquote()

---
 src/backend/utils/adt/jsonb.c | 31 +++++++++++++++++++++++++++++++
 src/include/utils/jsonb.h     |  1 +
 2 files changed, 32 insertions(+)

diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 6f445f5c2b..e5dca46b96 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -2163,3 +2163,34 @@ jsonb_float8(PG_FUNCTION_ARGS)
 
 	PG_RETURN_DATUM(retValue);
 }
+
+/*
+ * Convert jsonb to a C-string stripping quotes from scalar strings.
+ */
+char *
+JsonbUnquote(Jsonb *jb)
+{
+	if (JB_ROOT_IS_SCALAR(jb))
+	{
+		JsonbValue	v;
+
+		(void) JsonbExtractScalar(&jb->root, &v);
+
+		if (v.type == jbvString)
+			return pnstrdup(v.val.string.val, v.val.string.len);
+		else if (v.type == jbvBool)
+			return pstrdup(v.val.boolean ? "true" : "false");
+		else if (v.type == jbvNumeric)
+			return DatumGetCString(DirectFunctionCall1(numeric_out,
+													   PointerGetDatum(v.val.numeric)));
+		else if (v.type == jbvNull)
+			return pstrdup("null");
+		else
+		{
+			elog(ERROR, "unrecognized jsonb value type %d", v.type);
+			return NULL;
+		}
+	}
+	else
+		return JsonbToCString(NULL, &jb->root, VARSIZE(jb));
+}
diff --git a/src/include/utils/jsonb.h b/src/include/utils/jsonb.h
index addc9b608e..613d5953f2 100644
--- a/src/include/utils/jsonb.h
+++ b/src/include/utils/jsonb.h
@@ -422,6 +422,7 @@ extern char *JsonbToCString(StringInfo out, JsonbContainer *in,
 							int estimated_len);
 extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
 								  int estimated_len);
+extern char *JsonbUnquote(Jsonb *jb);
 extern bool JsonbExtractScalar(JsonbContainer *jbc, JsonbValue *res);
 extern const char *JsonbTypeName(JsonbValue *val);
 
-- 
2.35.3