From 842592fb55b7877c975f2a8556e6c4c4c6b80722 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 13 Feb 2020 11:58:39 -0800
Subject: [PATCH] Extend field-cache infrastructure to support the Suunto EON
 Steel

This adds a few misc fields that the EON Steel wants, and changes the
string insertion interface to return a 'dc_status_t', which will be used
by that back-end.

The existing deepblu users don't care.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 src/field-cache.c | 20 +++++++++++++++-----
 src/field-cache.h | 18 ++++++++++++++++--
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/field-cache.c b/src/field-cache.c
index ee25f39..890320a 100644
--- a/src/field-cache.c
+++ b/src/field-cache.c
@@ -13,7 +13,7 @@
  * dynamically on the stack or whatever without having to
  * worry about it.
  */
-void dc_field_add_string(dc_field_cache_t *cache, const char *desc, const char *value)
+dc_status_t dc_field_add_string(dc_field_cache_t *cache, const char *desc, const char *value)
 {
 	int i;
 
@@ -22,23 +22,33 @@ void dc_field_add_string(dc_field_cache_t *cache, const char *desc, const char *
 		dc_field_string_t *str = cache->strings+i;
 		if (str->desc)
 			continue;
-		str->desc = desc;
 		str->value = strdup(value);
-		break;
+		if (!str->value)
+			return DC_STATUS_NOMEMORY;
+		str->desc = desc;
+		return DC_STATUS_SUCCESS;
 	}
+	return DC_STATUS_INVALIDARGS;
 }
 
-void dc_field_add_string_fmt(dc_field_cache_t *cache, const char *desc, const char *fmt, ...)
+dc_status_t dc_field_add_string_fmt(dc_field_cache_t *cache, const char *desc, const char *fmt, ...)
 {
 	char buffer[256];
 	va_list ap;
 
+	/*
+	 * We ignore the return value from vsnprintf, and we
+	 * always NUL-terminate the destination buffer ourselves.
+	 *
+	 * That way we don't have to worry about random bad legacy
+	 * implementations.
+	 */
 	va_start(ap, fmt);
 	buffer[sizeof(buffer)-1] = 0;
 	(void) vsnprintf(buffer, sizeof(buffer)-1, fmt, ap);
 	va_end(ap);
 
-	dc_field_add_string(cache, desc, buffer);
+	return dc_field_add_string(cache, desc, buffer);
 }
 
 dc_status_t dc_field_get_string(dc_field_cache_t *cache, unsigned idx, dc_field_string_t *value)
diff --git a/src/field-cache.h b/src/field-cache.h
index 87a4c6c..0fc21d5 100644
--- a/src/field-cache.h
+++ b/src/field-cache.h
@@ -5,6 +5,7 @@
 typedef struct dc_field_cache {
 	unsigned int initialized;
 
+	// DC_GET_FIELD_xyz
 	unsigned int DIVETIME;
 	double MAXDEPTH;
 	double AVGDEPTH;
@@ -14,11 +15,24 @@ typedef struct dc_field_cache {
 	dc_salinity_t SALINITY;
 	dc_gasmix_t GASMIX[MAXGASES];
 
+	// misc - clean me up!
+	double lowsetpoint;
+	double highsetpoint;
+	double customsetpoint;
+
+	// This (slong with GASMIX) should be something like
+	//     dc_tank_t TANK[MAXGASES]
+	// but that's for later
+	dc_tankinfo_t tankinfo[MAXGASES];
+	double tanksize[MAXGASES];
+	double tankworkingpressure[MAXGASES];
+
+	// DC_GET_FIELD_STRING
 	dc_field_string_t strings[MAXSTRINGS];
 } dc_field_cache_t;
 
-void dc_field_add_string(dc_field_cache_t *, const char *desc, const char *data);
-void dc_field_add_string_fmt(dc_field_cache_t *, const char *desc, const char *fmt, ...);
+dc_status_t dc_field_add_string(dc_field_cache_t *, const char *desc, const char *data);
+dc_status_t dc_field_add_string_fmt(dc_field_cache_t *, const char *desc, const char *fmt, ...);
 dc_status_t dc_field_get_string(dc_field_cache_t *, unsigned idx, dc_field_string_t *value);
 
 /*