commit 72fdff1fdb5b82685dc3d2db23ece042195a0cbd
Author: Christopher Faulet <cfaulet@haproxy.com>
Date:   Fri Apr 26 14:30:15 2019 +0200

    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.
    
    (cherry picked from commit 85db3212b87b33f1a39a688546f4f53a5c4ba4da)
    Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
    (cherry picked from commit b93366e3ee44f5de93f01569fcdcd602f6d0703f)
    Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/include/proto/spoe.h b/include/proto/spoe.h
index 2cdca10b..cce13e50 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 chunk *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 0c0b3794..66d8b045 100644
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -2187,7 +2187,9 @@ spoe_encode_message(struct stream *s, struct spoe_context *ctx,
 
 		/* Fetch the arguement 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;
 	}