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, 64 insertions, 45 deletions

diff --git a/libcrystfel/src/image-hdf5.c b/libcrystfel/src/image-hdf5.c
index c939e136..2995654d 100644
--- a/libcrystfel/src/image-hdf5.c
+++ b/libcrystfel/src/image-hdf5.c
@@ -633,8 +633,7 @@ int image_hdf5_read_mask(struct panel_template *p,
 }
 
 
-double image_hdf5_get_value(const char *name, const char *filename,
-                            const char *event, char *ptype)
+int image_hdf5_read_header_to_cache(struct image *image, const char *name)
 {
 	hid_t dh;
 	hid_t type;
@@ -653,47 +652,44 @@ double image_hdf5_get_value(const char *name, const char *filename,
 	int i;
 	char *subst_name = NULL;
 	hid_t fh;
-	double val;
 	int *dim_vals;
 	int n_dim_vals;
 	int dim_val_pos;
 
-	if ( access(filename, R_OK) == -1 ) {
-		ERROR("File does not exist or cannot be read: %s\n", filename);
-		return NAN;
+	if ( access(image->filename, R_OK) == -1 ) {
+		ERROR("File does not exist or cannot be read: %s\n",
+		      image->filename);
+		return 1;
 	}
 
-	fh = H5Fopen(filename, H5F_ACC_RDONLY, H5P_DEFAULT);
+	fh = H5Fopen(image->filename, H5F_ACC_RDONLY, H5P_DEFAULT);
 	if ( fh < 0 ) {
-		ERROR("Couldn't open file: %s\n", filename);
-		return NAN;
+		ERROR("Couldn't open file: %s\n", image->filename);
+		return 1;
 	}
 
-	subst_name = substitute_path(event, name, 1);
+	subst_name = substitute_path(image->ev, name, 1);
 	if ( subst_name == NULL ) {
-		ERROR("Invalid event ID '%s'\n", event);
+		ERROR("Invalid event ID '%s'\n", image->ev);
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
 	dh = H5Dopen2(fh, subst_name, H5P_DEFAULT);
 	if ( dh < 0 ) {
 		ERROR("No such numeric field '%s'\n", subst_name);
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
 	type = H5Dget_type(dh);
 	class = H5Tget_class(type);
 
-	if ( class == H5T_FLOAT ) {
-		*ptype = 'f';
-	} else if ( class == H5T_INTEGER ) {
-		*ptype = 'i';
-	} else {
+	/* FIXME: Handle strings as well */
+	if ( (class != H5T_FLOAT) && (class != H5T_INTEGER) ) {
 		ERROR("Not a floating point or integer value.\n");
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
 	/* Get the dimensionality.  We have to cope with scalars expressed as
@@ -703,7 +699,7 @@ double image_hdf5_get_value(const char *name, const char *filename,
 	if ( ndims > 64 ) {
 		ERROR("Too many dimensions for numeric value\n");
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 	H5Sget_simple_extent_dims(sh, size, NULL);
 
@@ -719,37 +715,42 @@ double image_hdf5_get_value(const char *name, const char *filename,
 
 		if ( class == H5T_FLOAT ) {
 
-			r = H5Dread(dh, H5T_NATIVE_DOUBLE, ms, sh, H5P_DEFAULT, &val);
+			double val;
+			r = H5Dread(dh, H5T_NATIVE_DOUBLE, ms, sh, H5P_DEFAULT,
+			            &val);
 			if ( r < 0 )  {
 				ERROR("Couldn't read scalar value from %s.\n",
 				      subst_name);
 				free(subst_name);
 				close_hdf5(fh);
-				return NAN;
+				return 1;
 			}
-			return val;
+			image_cache_header_float(image, name, val);
+			return 0;
 
 		} else {
 
-			int vali;
-			r = H5Dread(dh, H5T_NATIVE_INT, ms, sh, H5P_DEFAULT, &vali);
+			int val;
+			r = H5Dread(dh, H5T_NATIVE_INT, ms, sh, H5P_DEFAULT,
+			            &val);
 			if ( r < 0 )  {
 				ERROR("Couldn't read scalar value from %s.\n",
 				      subst_name);
 				free(subst_name);
 				close_hdf5(fh);
-				return NAN;
+				return 1;
 			}
-			return vali;
+			image_cache_header_int(image, name, val);
+			return 0;
 
 		}
 	}
 
-	dim_vals = read_dim_parts(event, &n_dim_vals);
+	dim_vals = read_dim_parts(image->ev, &n_dim_vals);
 	if ( dim_vals == NULL ) {
 		ERROR("Couldn't parse event '%s'\n");
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
 	f_offset = malloc(ndims*sizeof(hsize_t));
@@ -757,7 +758,7 @@ double image_hdf5_get_value(const char *name, const char *filename,
 	if ( (f_offset == NULL) || (f_count == NULL) ) {
 		ERROR("Couldn't allocate dimension arrays\n");
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
 	/* Every dimension of the dataset must either be size 1 or
@@ -774,7 +775,7 @@ double image_hdf5_get_value(const char *name, const char *filename,
 				      subst_name, i,
 				      dim_vals[dim_val_pos], size[i]);
 				close_hdf5(fh);
-				return NAN;
+				return 1;
 			}
 
 			f_offset[i] = dim_vals[dim_val_pos];
@@ -790,6 +791,8 @@ double image_hdf5_get_value(const char *name, const char *filename,
 
 	}
 
+	free(subst_name);
+
 	check = H5Sselect_hyperslab(sh, H5S_SELECT_SET,
 	                            f_offset, NULL, f_count, NULL);
 	if ( check <0 ) {
@@ -797,33 +800,49 @@ double image_hdf5_get_value(const char *name, const char *filename,
 		free(f_offset);
 		free(f_count);
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
+	free(f_offset);
+	free(f_count);
+
 	ms = H5Screate_simple(1,msdims,NULL);
 	check = H5Sselect_hyperslab(ms, H5S_SELECT_SET,
 	                            m_offset, NULL, m_count, NULL);
 	if ( check < 0 ) {
 		ERROR("Error selecting memory dataspace for float value\n");
-		free(f_offset);
-		free(f_count);
 		close_hdf5(fh);
-		return NAN;
+		return 1;
 	}
 
-	r = H5Dread(dh, H5T_NATIVE_DOUBLE, ms, sh, H5P_DEFAULT, &val);
-	if ( r < 0 )  {
-		ERROR("Couldn't read value.\n");
+	if ( class == H5T_FLOAT ) {
+
+		double val;
+		r = H5Dread(dh, H5T_NATIVE_DOUBLE, ms, sh, H5P_DEFAULT, &val);
+		if ( r < 0 )  {
+			ERROR("Couldn't read value.\n");
+			close_hdf5(fh);
+			return 1;
+		}
+
+		image_cache_header_float(image, name, val);
 		close_hdf5(fh);
-		return NAN;
-	}
+		return 0;
 
-	free(f_offset);
-	free(f_count);
-	free(subst_name);
-	close_hdf5(fh);
+	} else {
 
-	return val;
+		int val;
+		r = H5Dread(dh, H5T_NATIVE_INT, ms, sh, H5P_DEFAULT, &val);
+		if ( r < 0 )  {
+			ERROR("Couldn't read value.\n");
+			close_hdf5(fh);
+			return 1;
+		}
+
+		image_cache_header_int(image, name, val);
+		close_hdf5(fh);
+		return 0;
+	}
 }