From 85db3212b87b33f1a39a688546f4f53a5c4ba4da Mon Sep 17 00:00:00 2001
From: Christopher Faulet <cfaulet@haproxy.com>
Date: Fri, 26 Apr 2019 14:30:15 +0200
Subject: [PATCH] MINOR: spoe: Use the sample context to pass frag_ctx info
 during encoding

This simplifies the API and hide the details in the sample. This way, only
string and binary are aware of these info, because other types cannot be
partially encoded.

This patch may be backported to 1.9 and 1.8.
---
 include/proto/spoe.h | 18 ++++++++++--------
 src/flt_spoe.c       |  4 +++-
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/include/proto/spoe.h b/include/proto/spoe.h
index 86328adef..c840c887b 100644
--- a/include/proto/spoe.h
+++ b/include/proto/spoe.h
@@ -117,11 +117,9 @@ spoe_decode_buffer(char **buf, char *end, char **str, uint64_t *len)
  *
  * If the value is too big to be encoded, depending on its type, then encoding
  * failed or the value is partially encoded. Only strings and binaries can be
- * partially encoded. In this case, the offset <*off> is updated to known how
- * many bytes has been encoded. If <*off> is zero at the end, it means that all
- * data has been encoded. */
+ * partially encoded. */
 static inline int
-spoe_encode_data(unsigned int *len, struct sample *smp, unsigned int *off, char **buf, char *end)
+spoe_encode_data(struct sample *smp, char **buf, char *end)
 {
 	char *p = *buf;
 	int   ret;
@@ -164,12 +162,16 @@ spoe_encode_data(unsigned int *len, struct sample *smp, unsigned int *off, char
 
 		case SMP_T_STR:
 		case SMP_T_BIN: {
+			/* If defined, get length and offset of the sample by reading the sample
+			 * context. ctx.a[0] is the pointer to the length and ctx.a[1] is the
+			 * pointer to the offset. If the offset is greater than 0, it means the
+			 * sample is partially encoded. In this case, we only need to encode the
+			 * reamining. When all the sample is encoded, the offset is reset to 0.
+			 * So the caller know it can try to encode the next sample. */
 			struct buffer *chk = &smp->data.u.str;
+			unsigned int *len  = (smp->ctx.a[0] ? smp->ctx.a[0] : 0);
+			unsigned int *off  = (smp->ctx.a[1] ? smp->ctx.a[1] : 0);
 
-			/* Here, we need to know if the sample has already been
-			 * partially encoded. If yes, we only need to encode the
-			 * remaining, <*off> reprensenting the number of bytes
-			 * already encoded. */
 			if (!*off) {
 				/* First evaluation of the sample : encode the
 				 * type (string or binary), the buffer length
diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index 609fa306f..2d70aff5b 100644
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -2197,7 +2197,9 @@ spoe_encode_message(struct stream *s, struct spoe_context *ctx,
 
 		/* Fetch the argument value */
 		smp = sample_process(s->be, s->sess, s, dir|SMP_OPT_FINAL, arg->expr, NULL);
-		ret = spoe_encode_data(&ctx->frag_ctx.curlen, smp, &ctx->frag_ctx.curoff, buf, end);
+		smp->ctx.a[0] = &ctx->frag_ctx.curlen;
+		smp->ctx.a[1] = &ctx->frag_ctx.curoff;
+		ret = spoe_encode_data(smp, buf, end);
 		if (ret == -1 || ctx->frag_ctx.curoff)
 			goto too_big;
 	}