Rework header caching layer

This clears up multiple layering violations which were starting to get
in the way.  It enables "string" headers to be stored directly, and it
will make it much simpler to add new header types in the future.

Along the way, this changes all the floating point header stuff to use
double precision.  This is needed for EuXFEL event IDs.

Closes: https://gitlab.desy.de/thomas.white/crystfel/-/issues/34

1 files changed, 48 insertions, 16 deletions

diff --git a/libcrystfel/src/stream.c b/libcrystfel/src/stream.c
index 89f59ddc..47438614 100644
--- a/libcrystfel/src/stream.c
+++ b/libcrystfel/src/stream.c
@@ -638,15 +638,27 @@ int stream_write_chunk(Stream *st, const struct image *i,
 
 	for ( j=0; j<i->n_cached_headers; j++ ) {
 		struct header_cache_entry *ce = i->header_cache[j];
-		if ( ce->type == 'f' ) {
+		switch ( ce->type ) {
+
+			case HEADER_FLOAT:
 			fprintf(st->fh, "header/float/%s = %f\n",
 			        ce->header_name, ce->val_float);
-		} else if ( ce->type == 'i' ) {
+			break;
+
+			case HEADER_INT:
 			fprintf(st->fh, "header/int/%s = %i\n",
 			        ce->header_name, ce->val_int);
-		} else {
-			ERROR("Unrecognised header cache type '%c'\n",
-			      ce->type);
+			break;
+
+			case HEADER_STR:
+			fprintf(st->fh, "header/str/%s = %s\n",
+			        ce->header_name, ce->val_str);
+			break;
+
+			default:
+			ERROR("Unrecognised header cache type %i\n", ce->type);
+			break;
+
 		}
 	}
 
@@ -899,12 +911,14 @@ static void read_crystal(Stream *st, struct image *image,
 }
 
 
-static void parse_header(const char *line_in, struct image *image, char type)
+static void parse_header(const char *line_in, struct image *image,
+                         HeaderCacheType type)
 {
 	char *line;
 	char *pos;
 
 	line = strdup(line_in);
+	chomp(line);
 
 	pos = strchr(line, ' ');
 	if ( pos == NULL ) {
@@ -923,20 +937,34 @@ static void parse_header(const char *line_in, struct image *image, char type)
 		return;
 	}
 
-	if ( type == 'f' ) {
-		float v;
-		if ( sscanf(pos+3, "%f", &v) != 1 ) {
+	switch ( type ) {
+
+		double vf;
+		int vi;
+
+		case HEADER_FLOAT:
+		if ( convert_float(pos+3, &vf) != 0 ) {
 			ERROR("Invalid header line '%s' (invalid value)\n", line);
 			return;
 		}
-		image_cache_header_float(image, line, v);
-	} else {
-		int v;
-		if ( sscanf(pos+3, "%i", &v) != 1 ) {
+		image_cache_header_float(image, line, vf);
+		break;
+
+		case HEADER_INT:
+		if ( convert_int(pos+3, &vi) != 0 ) {
 			ERROR("Invalid header line '%s' (invalid value)\n", line);
 			return;
 		}
-		image_cache_header_int(image, line, v);
+		image_cache_header_int(image, line, vi);
+		break;
+
+		case HEADER_STR:
+		image_cache_header_str(image, line, pos+3);
+		break;
+
+		default:
+		ERROR("Unrecognised header cache type %i (from stream)\n", type);
+		break;
 	}
 }
 
@@ -983,11 +1011,15 @@ struct image *stream_read_chunk(Stream *st, StreamFlags srf)
 		}
 
 		if ( strncmp(line, "header/int/", 11) == 0 ) {
-			parse_header(line+11, image, 'i');
+			parse_header(line+11, image, HEADER_INT);
 		}
 
 		if ( strncmp(line, "header/float/", 13) == 0 ) {
-			parse_header(line+13, image, 'f');
+			parse_header(line+13, image, HEADER_FLOAT);
+		}
+
+		if ( strncmp(line, "header/str/", 13) == 0 ) {
+			parse_header(line+11, image, HEADER_STR);
 		}
 
 		if ( strncmp(line, "indexed_by = ", 13) == 0 ) {