Remove events.c, part 2

New event parsing, done at the last minute in image-hdf5.c

17 files changed, 949 insertions, 549 deletions

diff --git a/libcrystfel/src/datatemplate.c b/libcrystfel/src/datatemplate.c
index a34ec6f5..a34832f4 100644
--- a/libcrystfel/src/datatemplate.c
+++ b/libcrystfel/src/datatemplate.c
@@ -60,37 +60,28 @@ struct rgc_definition {
 
 static struct panel_template *new_panel(DataTemplate *det, const char *name)
 {
+	struct panel_template *copyme;
 	struct panel_template *new;
 
+	copyme = &det->defaults;
+
 	det->n_panels++;
 	det->panels = realloc(det->panels,
 	                      det->n_panels*sizeof(struct panel_template));
 
 	new = &det->panels[det->n_panels-1];
-	memcpy(new, &det->defaults, sizeof(struct panel_template));
+	memcpy(new, copyme, sizeof(struct panel_template));
 
+	/* Set name */
 	new->name = strdup(name);
 
 	/* Copy strings */
-	if ( new->cnz_from != NULL ) new->cnz_from = strdup(new->cnz_from);
-	if ( new->data != NULL ) new->data = strdup(new->data);
-	if ( new->mask != NULL ) new->mask = strdup(new->mask);
-
-	/* Create a new copy of the dim_structure if needed */
-	if ( new->dim_structure != NULL ) {
-
-		struct dim_structure *dim_copy;
-		int di;
-
-		dim_copy = initialize_dim_structure();
-		dim_copy->num_dims = new->dim_structure->num_dims;
-		dim_copy->dims = malloc(dim_copy->num_dims*sizeof(int));
-		for ( di=0; di<dim_copy->num_dims; di++ ) {
-			dim_copy->dims[di] = new->dim_structure->dims[di];
-		}
-
-		new->dim_structure = dim_copy;
-	}
+	new->cnz_from = safe_strdup(copyme->cnz_from);
+	new->data = safe_strdup(copyme->data);
+	new->mask = safe_strdup(copyme->mask);
+	new->mask_file = safe_strdup(copyme->mask_file);
+	new->satmap = safe_strdup(copyme->satmap);
+	new->satmap_file = safe_strdup(copyme->satmap_file);
 
 	return new;
 }
@@ -447,6 +438,34 @@ static int dir_conv(const char *a, double *sx, double *sy, double *sz)
 }
 
 
+int set_dim(struct panel_template *panel, int dimension,
+            const char *val)
+{
+	if ( dimension >= MAX_DIMS ) {
+		ERROR("Too many dimensions!\n");
+		return 1;
+	}
+
+	if ( strcmp(val, "fs") == 0 ) {
+		panel->dims[dimension] = DIM_FS;
+	} else if ( strcmp(val, "ss") == 0 ) {
+		panel->dims[dimension] = DIM_SS;
+	} else if ( strcmp(val, "%") == 0 ) {
+		panel->dims[dimension] = DIM_PLACEHOLDER;
+	} else {
+		char *endptr;
+		unsigned long int fix_val = strtoul(val, &endptr, 10);
+		if ( endptr[0] != '\0' ) {
+			ERROR("Invalid dimension value '%s'\n", val);
+			return 1;
+		} else {
+			panel->dims[dimension] = fix_val;
+		}
+	}
+	return 0;
+}
+
+
 static int parse_field_for_panel(struct panel_template *panel, const char *key,
                                  const char *val, DataTemplate *det)
 {
@@ -534,16 +553,12 @@ static int parse_field_for_panel(struct panel_template *panel, const char *key,
 		int dim_entry;
 		char *endptr;
 		if ( key[3] != '\0' ) {
-			if  ( panel->dim_structure == NULL ) {
-				panel->dim_structure = initialize_dim_structure();
-			}
 			dim_entry = strtoul(key+3, &endptr, 10);
 			if ( endptr[0] != '\0' ) {
-				ERROR("Invalid dimension number %s\n", key+3);
+				ERROR("Invalid dimension number %s\n",
+				      key+3);
 			} else {
-				if ( set_dim_structure_entry(panel->dim_structure,
-				                        dim_entry, val) )
-				{
+				if ( set_dim(panel, dim_entry, val) ) {
 					ERROR("Failed to set dim structure entry\n");
 				}
 			}
@@ -703,10 +718,6 @@ DataTemplate *data_template_new_from_string(const char *string_in)
 	int i;
 	int rgi, rgci;
 	int reject = 0;
-	int path_dim, mask_path_dim;
-	int dim_dim;
-	int dim_reject = 0;
-	int dim_dim_reject = 0;
 	struct rg_definition **rg_defl = NULL;
 	struct rgc_definition **rgc_defl = NULL;
 	int n_rg_definitions = 0;
@@ -726,8 +737,6 @@ DataTemplate *data_template_new_from_string(const char *string_in)
 	dt->mask_bad = 0;
 	dt->n_rigid_groups = 0;
 	dt->rigid_groups = NULL;
-	dt->path_dim = 0;
-	dt->dim_dim = 0;
 	dt->n_rg_collections = 0;
 	dt->rigid_group_collections = NULL;
 	dt->photon_energy_bandwidth = -1.0;
@@ -763,7 +772,7 @@ DataTemplate *data_template_new_from_string(const char *string_in)
 	dt->defaults.satmap = NULL;
 	dt->defaults.satmap_file = NULL;
 	dt->defaults.data = NULL;
-	dt->defaults.dim_structure = NULL;
+	for ( i=0; i<MAX_DIMS; i++ ) dt->defaults.dims[i] = DIM_UNDEFINED;
 	dt->defaults.name = NULL;
 
 	string = strdup(string_in);
@@ -882,151 +891,6 @@ DataTemplate *data_template_new_from_string(const char *string_in)
 		return NULL;
 	}
 
-	path_dim = -1;
-	dim_reject = 0;
-
-	for ( i=0; i<dt->n_panels; i++ ) {
-
-		int panel_dim = 0;
-		char *next_instance;
-
-		next_instance = dt->panels[i].data;
-
-		while ( next_instance ) {
-			next_instance = strstr(next_instance, "%");
-			if ( next_instance != NULL ) {
-				next_instance += 1*sizeof(char);
-				panel_dim += 1;
-			}
-		}
-
-		if ( path_dim == -1 ) {
-			path_dim = panel_dim;
-		} else {
-			if ( panel_dim != path_dim ) {
-				dim_reject = 1;
-			}
-		}
-
-	}
-
-	mask_path_dim = -1;
-	for ( i=0; i<dt->n_panels; i++ ) {
-
-		int panel_mask_dim = 0;
-		char *next_instance;
-
-		if ( dt->panels[i].mask != NULL ) {
-
-			next_instance = dt->panels[i].mask;
-
-			while ( next_instance ) {
-				next_instance = strstr(next_instance, "%");
-				if ( next_instance != NULL ) {
-					next_instance += 1*sizeof(char);
-					panel_mask_dim += 1;
-				}
-			}
-
-			if ( mask_path_dim == -1 ) {
-				mask_path_dim = panel_mask_dim;
-			} else {
-				if ( panel_mask_dim != mask_path_dim ) {
-					dim_reject = 1;
-				}
-			}
-
-		}
-	}
-
-	if ( dim_reject ==  1 ) {
-		ERROR("All panels' data and mask entries must have the same "
-		      "number of placeholders\n");
-		reject = 1;
-	}
-
-	if ( mask_path_dim > path_dim ) {
-		ERROR("Number of placeholders in mask cannot be larger than "
-		      "for data\n");
-		reject = 1;
-	}
-
-	dt->path_dim = path_dim;
-
-	dim_dim_reject = 0;
-	dim_dim = -1;
-
-	for ( i=0; i<dt->n_panels; i++ ) {
-
-		int di;
-		int found_ss = 0;
-		int found_fs = 0;
-		int panel_dim_dim = 0;
-
-		if ( dt->panels[i].dim_structure == NULL ) {
-			dt->panels[i].dim_structure = default_dim_structure();
-		}
-
-		for ( di=0; di<dt->panels[i].dim_structure->num_dims; di++ ) {
-
-			if ( dt->panels[i].dim_structure->dims[di] ==
-			                                   HYSL_UNDEFINED  ) {
-				dim_dim_reject = 1;
-				ERROR("Dimension %i for panel %s is undefined.\n",
-				      di, dt->panels[i].name);
-			}
-			if ( dt->panels[i].dim_structure->dims[di] ==
-			                                   HYSL_PLACEHOLDER  ) {
-				panel_dim_dim += 1;
-			}
-			if ( dt->panels[i].dim_structure->dims[di] ==
-			                                   HYSL_SS  ) {
-				found_ss += 1;
-			}
-			if ( dt->panels[i].dim_structure->dims[di] ==
-			                                   HYSL_FS  ) {
-				found_fs += 1;
-			}
-
-		}
-
-		if ( found_ss != 1 ) {
-			ERROR("Exactly one slow scan dim coordinate is needed "
-			      "(found %i for panel %s)\n", found_ss,
-			      dt->panels[i].name);
-			dim_dim_reject = 1;
-		}
-
-		if ( found_fs != 1 ) {
-			ERROR("Exactly one fast scan dim coordinate is needed "
-			      "(found %i for panel %s)\n", found_fs,
-			      dt->panels[i].name);
-			dim_dim_reject = 1;
-		}
-
-		if ( panel_dim_dim > 1 ) {
-			ERROR("Maximum one placeholder dim coordinate is "
-			      "allowed (found %i for panel %s)\n",
-			      panel_dim_dim, dt->panels[i].name);
-			dim_dim_reject = 1;
-		}
-
-		if ( dim_dim == -1 ) {
-			dim_dim = panel_dim_dim;
-		} else {
-			if ( panel_dim_dim != dim_dim ) {
-				dim_dim_reject = 1;
-			}
-		}
-
-	}
-
-	if ( dim_dim_reject ==  1) {
-		reject = 1;
-	}
-
-	dt->dim_dim = dim_dim;
-
 	for ( i=0; i<dt->n_panels; i++ ) {
 
 		struct panel_template *p = &dt->panels[i];
@@ -1241,10 +1105,17 @@ void data_template_free(DataTemplate *dt)
 	free_all_rigid_group_collections(dt);
 
 	for ( i=0; i<dt->n_panels; i++ ) {
+		free(dt->panels[i].name);
+		free(dt->panels[i].mask);
+		free(dt->panels[i].mask_file);
+		free(dt->panels[i].satmap);
+		free(dt->panels[i].satmap_file);
 		free(dt->panels[i].cnz_from);
-		free_dim_structure(dt->panels[i].dim_structure);
 	}
 
+	free(dt->wavelength_from);
+	free(dt->peak_list);
+
 	free(dt->panels);
 	free(dt->bad);
 	free(dt);
@@ -1433,6 +1304,17 @@ struct detgeom *data_template_to_detgeom(const DataTemplate *dt)
 }
 
 
+static int num_placeholders(const struct panel_template *p)
+{
+	int i;
+	int n_pl = 0;
+	for ( i=0; i<MAX_DIMS; i++ ) {
+		if ( p->dims[i] == DIM_PLACEHOLDER ) n_pl++;
+	}
+	return n_pl;
+}
+
+
 int data_template_get_slab_extents(const DataTemplate *dt,
                                    int *pw, int *ph)
 {
@@ -1452,14 +1334,9 @@ int data_template_get_slab_extents(const DataTemplate *dt,
 			return 1;
 		}
 
-		if ( p->dim_structure != NULL ) {
-			int j;
-			for ( j=0; j<p->dim_structure->num_dims; j++ ) {
-				if ( p->dim_structure->dims[j] == HYSL_PLACEHOLDER ) {
-					/* Not slabby */
-					return 1;
-				}
-			}
+		if ( num_placeholders(p) > 0 ) {
+			/* Not slabby */
+			return 1;
 		}
 
 		if ( p->orig_max_fs > w ) {
@@ -1468,6 +1345,7 @@ int data_template_get_slab_extents(const DataTemplate *dt,
 		if ( p->orig_max_ss > h ) {
 			h = p->orig_max_ss;
 		}
+
 	}
 
 	/* Inclusive -> exclusive */
diff --git a/libcrystfel/src/datatemplate_priv.h b/libcrystfel/src/datatemplate_priv.h
index 75e9adfe..0cf2f025 100644
--- a/libcrystfel/src/datatemplate_priv.h
+++ b/libcrystfel/src/datatemplate_priv.h
@@ -32,6 +32,12 @@
 #ifndef DATATEMPLATE_PRIV_H
 #define DATATEMPLATE_PRIV_H
 
+/* Maximum number of dimensions expected in data files */
+#define MAX_DIMS (16)
+
+/* Maximum number of placeholders expected in path structure */
+#define MAX_PATH_PARTS (16)
+
 enum adu_per_unit
 {
 	ADU_PER_PHOTON,
@@ -55,6 +61,12 @@ struct dt_rg_collection
 };
 
 
+/* Special values for dimension IDs */
+#define DIM_FS (-1)
+#define DIM_SS (-2)
+#define DIM_UNDEFINED (-3)
+#define DIM_PLACEHOLDER (-4)
+
 /**
  * Represents one panel of a detector
  */
@@ -100,11 +112,11 @@ struct panel_template
 	/** Treat pixel as unreliable if higher than this */
 	double max_adu;
 
-	/** Location of data in file */
+	/** Location of data in file (possibly with placeholders) */
 	char *data;
 
-	/** Dimension structure */
-	struct dim_structure *dim_structure;
+	/** Dimensions (see definitions for DIM_FS etc above) */
+	signed int dims[MAX_DIMS];
 
 	/** \name Transformation matrix from pixel coordinates to lab frame */
 	/*@{*/
@@ -177,9 +189,6 @@ struct _datatemplate
 	struct dt_rg_collection  **rigid_group_collections;
 	int                        n_rg_collections;
 
-	int                        path_dim;
-	int                        dim_dim;
-
 	char                      *peak_list;
 
 	struct panel_template      defaults;  /* FIXME: Shouldn't be stored */
diff --git a/libcrystfel/src/image-cbf.c b/libcrystfel/src/image-cbf.c
index d2d0eca1..5b27c5a5 100644
--- a/libcrystfel/src/image-cbf.c
+++ b/libcrystfel/src/image-cbf.c
@@ -506,7 +506,7 @@ signed int is_cbf_file(const char *filename)
 	fh = fopen(filename, "r");
 	if ( fh == NULL ) return -1;
 
-	if ( fgets(line, 1024, fh) == NULL ) return -1;
+	if ( fgets(line, 1024, fh) == NULL ) return 0;
 	fclose(fh);
 
 	if ( strstr(line, "CBF") == NULL ) {
@@ -524,7 +524,7 @@ signed int is_cbfgz_file(const char *filename)
 
 	gzfh = gzopen(filename, "rb");
 	if ( gzfh == NULL ) return -1;
-	if ( gzgets(gzfh, line, 1024) == NULL ) return -1;
+	if ( gzgets(gzfh, line, 1024) == NULL ) return 0;
 	gzclose(gzfh);
 
 	if ( strstr(line, "CBF") == NULL ) {
diff --git a/libcrystfel/src/image-hdf5.c b/libcrystfel/src/image-hdf5.c
index 9a7b17ce..13d0c5ed 100644
--- a/libcrystfel/src/image-hdf5.c
+++ b/libcrystfel/src/image-hdf5.c
@@ -7,7 +7,8 @@
  *                       a research centre of the Helmholtz Association.
  *
  * Authors:
- *   2020 Thomas White <taw@physics.org>
+ *   2020      Thomas White <taw@physics.org>
+ *   2014-2018 Valerio Mariani
  *
  * This file is part of CrystFEL.
  *
@@ -43,6 +44,246 @@
 #include "datatemplate_priv.h"
 
 
+/* Get the path parts of the event ID
+ * e.g. ev_orig = abc/def/ghi//5/2/7
+ *     -> [abc, def, ghi], with *pn_plvals=3 */
+static char **read_path_parts(const char *ev_orig, int *pn_plvals)
+{
+	char **plvals;
+	char *ev;
+	int n_plvals = 0;
+	char *start;
+
+	plvals = malloc(MAX_PATH_PARTS*sizeof(char *));
+	if ( plvals == NULL ) return NULL;
+
+	if ( ev_orig == NULL ) {
+		/* No ev -> no path parts */
+		*pn_plvals = 0;
+		return plvals;
+	}
+
+	ev = strdup(ev_orig);
+	if ( ev == NULL ) return NULL;
+
+	start = ev;
+	do {
+
+		char *sep;
+
+		sep = strchr(start, '/');
+
+		if ( sep == NULL ) {
+			/* This would be very strange, because it
+			 * must at least have // */
+			ERROR("Couldn't read path parts ('%s')\n",
+			      start);
+			free(ev);
+			free(plvals);
+			return NULL;
+		}
+
+		/* Remaining string starts with '/' is end condition */
+		if ( sep == start ) break;
+
+		if ( n_plvals == MAX_PATH_PARTS ) {
+			ERROR("Too many path parts: %s\n", ev_orig);
+			free(ev);
+			free(plvals);
+			return NULL;
+		}
+
+		sep[0] = '\0';
+		plvals[n_plvals++] = strdup(start);
+
+		start = sep+1;
+
+	} while ( 1 );
+
+	free(ev);
+	*pn_plvals = n_plvals;
+	return plvals;
+}
+
+
+/* Get the dimension parts of the event ID
+ * e.g. ev_orig = abc/def/ghi//5/2/7
+ *     -> [5, 2, 7], with *pn_dvals=3 */
+static int *read_dim_parts(const char *ev_orig, int *pn_dvals)
+
+{
+	char *ev;
+	int n_dvals = 0;
+	int *dvals;
+	char *start;
+	int done;
+
+	/* Valid event ID? (Just the part after //, please) */
+	ev = strstr(ev_orig, "//");
+	if ( ev == NULL ) return NULL;
+
+	dvals = malloc(MAX_DIMS*sizeof(int));
+	if ( dvals == NULL ) return NULL;
+
+	if ( ev[2] == '\0' ) {
+		/* No dimension parts - early bailout */
+		*pn_dvals = 0;
+		return dvals;  /* NB Not NULL */
+	}
+
+	ev = strdup(ev+2);
+	if ( ev == NULL ) return NULL;
+
+	start = ev;
+	done = 0;
+	do {
+
+		char *sep = strchr(start, '/');
+
+		if ( sep != NULL ) {
+			sep[0] = '\0';
+		} else {
+			done = 1;
+		}
+
+		if ( n_dvals == MAX_PATH_PARTS ) {
+			ERROR("Too many path parts: %s\n", ev_orig);
+			free(ev);
+			free(dvals);
+			return NULL;
+		}
+
+		if ( start[0] == '\0' ) {
+			ERROR("Missing dimension: %s\n", ev_orig);
+			free(ev);
+			free(dvals);
+			return NULL;
+		}
+
+		dvals[n_dvals++] = atoi(start);
+
+		start = sep+1;
+
+	} while ( !done );
+
+	free(ev);
+	*pn_dvals = n_dvals;
+	return dvals;
+}
+
+
+/* ev = abc/def/ghi//5/2/7
+ * pattern = /data/%/somewhere/%/%/data
+ * output = /data/abc/somewhere/def/ghi/data
+ */
+static char *substitute_path(const char *ev, const char *pattern)
+{
+	char **plvals;
+	int n_plvals;
+	int n_pl_exp;
+	size_t l, total_len;
+	int i;
+	char *subs;
+	const char *start;
+	const char *pl_pos;
+
+	if ( pattern == NULL ) {
+		ERROR("Pattern cannot be NULL\n");
+		return NULL;
+	}
+
+	plvals = read_path_parts(ev, &n_plvals);
+	if ( plvals == NULL ) return NULL;
+
+	l = strlen(pattern);
+	n_pl_exp = 0;
+	for ( i=0; i<l; i++ ) {
+		if ( pattern[i] == '%' ) n_pl_exp++;
+	}
+
+	if ( n_plvals != n_pl_exp ) {
+		ERROR("Wrong number of path placeholders: "
+		      "'%s' into '%s'\n", ev, pattern);
+		return NULL;
+	}
+
+	total_len = strlen(pattern) - n_pl_exp;
+	for ( i=0; i<n_plvals; i++ ) {
+		total_len += strlen(plvals[i]);
+	}
+	subs = malloc(total_len+1);
+	if ( subs == NULL ) {
+		free(plvals);
+		return NULL;
+	}
+	subs[0] = '\0';
+
+	pl_pos = strchr(pattern, '%');
+	if ( pl_pos == NULL ) {
+		ERROR("Expected a placeholder char (%): '%s'\n",
+		      pattern);
+		return NULL;
+	}
+	strncpy(subs, pattern, pl_pos-pattern);
+
+	start = pl_pos+1;
+	for ( i=0; i<n_plvals; i++ ) {
+
+		/* Add the placeholder's value */
+		strcat(subs, plvals[i]);
+		free(plvals[i]);
+
+		/* Add the chars up to the next placeholder... */
+		pl_pos = strchr(start, '%');
+		if ( pl_pos == NULL ) {
+			/* ... or the end */
+			pl_pos = start+strlen(start);
+		}
+		strncat(subs, start, pl_pos-start);
+		start = pl_pos+1;
+	}
+
+	free(plvals);
+
+	return subs;
+}
+
+
+static void make_placeholder_skip(signed int *dt_dims,
+                                  signed int *panel_dims)
+{
+	int i;
+	int n_dt = 0;
+	for ( i=0; i<MAX_DIMS; i++ ) {
+		if ( panel_dims[i] != DIM_PLACEHOLDER ) {
+			dt_dims[n_dt++] = panel_dims[i];
+		}
+	}
+}
+
+
+static int num_placeholders(const struct panel_template *p)
+{
+	int i;
+	int n_pl = 0;
+	for ( i=0; i<MAX_DIMS; i++ ) {
+		if ( p->dims[i] == DIM_PLACEHOLDER ) n_pl++;
+	}
+	return n_pl;
+}
+
+
+static int total_dimensions(const struct panel_template *p)
+{
+	int i;
+	int n_dim = 0;
+	for ( i=0; i<MAX_DIMS; i++ ) {
+		if ( p->dims[i] != DIM_UNDEFINED ) n_dim++;
+	}
+	return n_dim;
+}
+
+
 static int load_hdf5_hyperslab(struct panel_template *p,
                                const char *filename,
                                const char *event,
@@ -51,19 +292,24 @@ static int load_hdf5_hyperslab(struct panel_template *p,
                                int skip_placeholders_ok,
                                const char *path_spec)
 {
-	struct event *ev;
 	hid_t fh;
+	int total_dt_dims;
+	int plh_dt_dims;
+	int dt_dims[MAX_DIMS];
+	int n_dt_dims;
 	herr_t r;
 	hsize_t *f_offset, *f_count;
 	hid_t dh;
-	int hsi;
 	herr_t check;
 	hid_t dataspace, memspace;
 	hsize_t dims[2];
 	char *panel_full_path;
 	void *data;
-	int ndims, dpos;
-	int skip_placeholders = 0;
+	int ndims;
+	int dim;
+	int *dim_vals;
+	int n_dim_vals;
+	int pl_pos;
 
 	if ( access(filename, R_OK) == -1 ) {
 		ERROR("File does not exist or cannot be read: %s\n",
@@ -77,21 +323,18 @@ static int load_hdf5_hyperslab(struct panel_template *p,
 		return 1;
 	}
 
-	ev = get_event_from_event_string(event);
-	if ( (ev == NULL) && (event != NULL) ) {
-		ERROR("Invalid event identifier '%s'\n", event);
-		H5Fclose(fh);
+	panel_full_path = substitute_path(event, path_spec);
+	if ( panel_full_path == NULL ) {
+		ERROR("Invalid path substitution: '%s' '%s'\n",
+		      event, path_spec);
 		return 1;
 	}
 
-	panel_full_path = retrieve_full_path(ev, path_spec);
-
 	dh = H5Dopen2(fh, panel_full_path, H5P_DEFAULT);
 	if ( dh < 0 ) {
 		ERROR("Cannot open data for panel %s (%s)\n",
 		      p->name, panel_full_path);
 		free(panel_full_path);
-		free_event(ev);
 		H5Fclose(fh);
 		return 1;
 	}
@@ -105,72 +348,84 @@ static int load_hdf5_hyperslab(struct panel_template *p,
 	if ( ndims < 0 ) {
 		ERROR("Failed to get number of dimensions for panel %s\n",
 		      p->name);
-		free_event(ev);
 		H5Fclose(fh);
 		return 1;
 	}
 
-	if ( ndims != p->dim_structure->num_dims ) {
-		/* Dimensionality doesn't match */
-		int n_nonplaceholder = 0;
-		for ( hsi=0; hsi<p->dim_structure->num_dims; hsi++ ) {
-			if ( p->dim_structure->dims[hsi] != HYSL_PLACEHOLDER ) {
-				n_nonplaceholder++;
-			}
-		}
-
+	/* Does the array have the expected number of dimensions? */
+	total_dt_dims = total_dimensions(p);
+	plh_dt_dims = num_placeholders(p);
+	if ( ndims != total_dt_dims ) {
 		/* If the dimensions match after excluding
 		 * placeholders, it's OK - probably a static mask
 		 * in a multi-event file. */
-		if ( ndims == n_nonplaceholder ) {
-			skip_placeholders = 1;
+		if ( skip_placeholders_ok
+		  && (ndims == total_dt_dims - plh_dt_dims) )
+		{
+			make_placeholder_skip(dt_dims, p->dims);
+			n_dt_dims = total_dt_dims - plh_dt_dims;
+		} else {
+			ERROR("Unexpected number of dimensions for "
+			      "panel %s (%i, but expected %i or %i)\n",
+			      p->name, ndims, total_dt_dims,
+			      total_dt_dims - plh_dt_dims);
+			H5Fclose(fh);
+			return 1;
 		}
+	} else {
+		int i;
+		for ( i=0; i<MAX_DIMS; i++ ) {
+			dt_dims[i] = p->dims[i];
+		}
+		n_dt_dims = total_dt_dims;
 	}
 
 	f_offset = malloc(ndims*sizeof(hsize_t));
 	f_count = malloc(ndims*sizeof(hsize_t));
 	if ( (f_offset == NULL) || (f_count == NULL ) ) {
 		ERROR("Failed to allocate offset or count.\n");
-		free_event(ev);
 		H5Fclose(fh);
 		return 1;
 	}
 
-	dpos = 0;
-	for ( hsi=0; hsi<p->dim_structure->num_dims; hsi++ ) {
+	/* Get those placeholder values from the event ID */
+	dim_vals = read_dim_parts(event, &n_dim_vals);
+
+	pl_pos = 0;
+	for ( dim=0; dim<n_dt_dims; dim++ ) {
 
-		switch ( p->dim_structure->dims[hsi] ) {
+		switch ( dt_dims[dim] ) {
 
-			case HYSL_FS:
-			f_offset[dpos] = p->orig_min_fs;
-			f_count[dpos] = p->orig_max_fs - p->orig_min_fs+1;
-			dpos++;
+			case DIM_FS:
+			f_offset[dim] = p->orig_min_fs;
+			f_count[dim] = p->orig_max_fs - p->orig_min_fs+1;
 			break;
 
-			case HYSL_SS:
-			f_offset[dpos] = p->orig_min_ss;
-			f_count[dpos] = p->orig_max_ss - p->orig_min_ss+1;
-			dpos++;
+			case DIM_SS:
+			f_offset[dim] = p->orig_min_ss;
+			f_count[dim] = p->orig_max_ss - p->orig_min_ss+1;
 			break;
 
-			case HYSL_PLACEHOLDER:
-			if ( !skip_placeholders ) {
-				f_offset[dpos] = ev->dim_entries[0];
-				f_count[dpos] = 1;
-				dpos++;
-			}
+			case DIM_PLACEHOLDER:
+			f_offset[dim] = dim_vals[pl_pos++];
+			f_count[dim] = 1;
+			break;
+
+			case DIM_UNDEFINED:
+			ERROR("Undefined dimension found!\n");
 			break;
 
 			default:
-			f_offset[dpos] = p->dim_structure->dims[hsi];
-			f_count[dpos] = 1;
-			dpos++;
+			/* Fixed value */
+			f_offset[dim] = dt_dims[dim];
+			f_count[dim] = 1;
 			break;
 
 		}
-
 	}
 
+	free(dim_vals);
+
 	check = H5Sselect_hyperslab(dataspace, H5S_SELECT_SET,
 	                            f_offset, NULL, f_count, NULL);
 	if ( check < 0 ) {
@@ -178,7 +433,6 @@ static int load_hdf5_hyperslab(struct panel_template *p,
 		      p->name);
 		free(f_offset);
 		free(f_count);
-		free_event(ev);
 		H5Fclose(fh);
 		return 1;
 	}
@@ -192,7 +446,6 @@ static int load_hdf5_hyperslab(struct panel_template *p,
 		ERROR("Failed to allocate panel %s\n", p->name);
 		free(f_offset);
 		free(f_count);
-		free_event(ev);
 		H5Fclose(fh);
 		return 1;
 	}
@@ -205,7 +458,6 @@ static int load_hdf5_hyperslab(struct panel_template *p,
 		free(f_offset);
 		free(f_count);
 		free(data);
-		free_event(ev);
 		H5Fclose(fh);
 		return 1;
 	}
@@ -214,7 +466,6 @@ static int load_hdf5_hyperslab(struct panel_template *p,
 	H5Sclose(dataspace);
 	free(f_offset);
 	free(f_count);
-	free_event(ev);
 	H5Fclose(fh);
 
 	*pdata = data;
@@ -319,9 +570,10 @@ double image_hdf5_get_value(const char *name, const char *filename,
 	int ndims;
 	int i;
 	char *subst_name = NULL;
-	struct event *ev;
 	hid_t fh;
 	double val;
+	int *dim_vals;
+	int n_dim_vals;
 
 	if ( access(filename, R_OK) == -1 ) {
 		ERROR("File does not exist or cannot be read: %s\n", filename);
@@ -333,15 +585,14 @@ double image_hdf5_get_value(const char *name, const char *filename,
 		ERROR("Couldn't open file: %s\n", filename);
 		return NAN;
 	}
-	ev = get_event_from_event_string(event);
-	if ( (ev == NULL) && (event != NULL) ) {
-		ERROR("Invalid event identifier '%s'\n", event);
+
+	subst_name = substitute_path(event, name);
+	if ( subst_name == NULL ) {
+		ERROR("Invalid event ID '%s'\n", event);
 		H5Fclose(fh);
 		return NAN;
 	}
 
-	subst_name = retrieve_full_path(ev, name);
-
 	dh = H5Dopen2(fh, subst_name, H5P_DEFAULT);
 	if ( dh < 0 ) {
 		ERROR("No such numeric field '%s'\n", subst_name);
@@ -371,10 +622,19 @@ double image_hdf5_get_value(const char *name, const char *filename,
 	}
 	H5Sget_simple_extent_dims(sh, size, NULL);
 
+	/* We expect a scalar value */
 	m_offset[0] = 0;
 	m_count[0] = 1;
 	msdims[0] = 1;
-	ms = H5Screate_simple(1,msdims,NULL);
+	ms = H5Screate_simple(1, msdims, NULL);
+
+	dim_vals = read_dim_parts(event, &n_dim_vals);
+	if ( dim_vals == NULL ) {
+		ERROR("Couldn't parse event '%s'\n");
+		H5Tclose(type);
+		H5Dclose(dh);
+		return NAN;
+	}
 
 	/* Check that the size in all dimensions is 1
 	 * or that one of the dimensions has the same
@@ -547,7 +807,7 @@ static int read_peak_count(hid_t fh, char *path, int line,
 }
 
 
-static float *read_hdf5_data(hid_t fh, char *path, int line)
+static float *read_peak_line(hid_t fh, char *path, int line)
 {
 
 	hid_t dh, sh, mh;
@@ -654,7 +914,6 @@ ImageFeatureList *image_hdf5_read_peaks_cxi(const DataTemplate *dtempl,
 	char path_i[1024];
 	int r;
 	int pk;
-	struct event *ev;
 	char *subst_name;
 
 	int line = 0;
@@ -678,22 +937,7 @@ ImageFeatureList *image_hdf5_read_peaks_cxi(const DataTemplate *dtempl,
 		return NULL;
 	}
 
-	ev = get_event_from_event_string(event);
-	if ( (ev == NULL) && (event != NULL) ) {
-		ERROR("Invalid event identifier '%s'\n", event);
-		H5Fclose(fh);
-		return NULL;
-	}
-
-	if ( ev->dim_entries == NULL ) {
-		ERROR("CXI format peak list format selected,"
-		      "but file has no event structure");
-		return NULL;
-	}
-	line = ev->dim_entries[0];
-
-	subst_name = retrieve_full_path(ev, dtempl->peak_list);
-	free_event(ev);
+	subst_name = substitute_path(event, dtempl->peak_list);
 	if ( subst_name == NULL ) {
 		ERROR("Invalid peak path %s\n", subst_name);
 		H5Fclose(fh);
@@ -708,13 +952,13 @@ ImageFeatureList *image_hdf5_read_peaks_cxi(const DataTemplate *dtempl,
 	r = read_peak_count(fh, path_n, line, &num_peaks);
 	if ( r != 0 ) return NULL;
 
-	buf_x = read_hdf5_data(fh, path_x, line);
+	buf_x = read_peak_line(fh, path_x, line);
 	if ( r != 0 ) return NULL;
 
-	buf_y = read_hdf5_data(fh, path_y, line);
+	buf_y = read_peak_line(fh, path_y, line);
 	if ( r != 0 ) return NULL;
 
-	buf_i = read_hdf5_data(fh, path_i, line);
+	buf_i = read_peak_line(fh, path_i, line);
 	if ( r != 0 ) return NULL;
 
 	features = image_feature_list_new();
@@ -757,7 +1001,6 @@ ImageFeatureList *image_hdf5_read_peaks_hdf5(const DataTemplate *dtempl,
 	float *buf;
 	herr_t r;
 	int tw;
-	struct event *ev;
 	char *subst_name;
 	ImageFeatureList *features;
 	double peak_offset = half_pixel_shift ? 0.5 : 0.0;
@@ -774,29 +1017,21 @@ ImageFeatureList *image_hdf5_read_peaks_hdf5(const DataTemplate *dtempl,
 		return NULL;
 	}
 
-	ev = get_event_from_event_string(event);
-	if ( (ev == NULL) && (event != NULL) ) {
-		ERROR("Invalid event identifier '%s'\n", event);
-		H5Fclose(fh);
-		return NULL;
-	}
-
-	subst_name = retrieve_full_path(ev, dtempl->peak_list);
-	free_event(ev);
+	subst_name = substitute_path(event, dtempl->peak_list);
 	if ( subst_name == NULL ) {
-		ERROR("Invalid peak path %s\n", subst_name);
-		free_event(ev);
-		H5Fclose(fh);
+		ERROR("Invalid peak path: '%s' '%s'\n",
+		      event, dtempl->peak_list);
 		return NULL;
 	}
 
 	dh = H5Dopen2(fh, subst_name, H5P_DEFAULT);
-	free(subst_name);
 	if ( dh < 0 ) {
 		ERROR("Peak list (%s) not found.\n", subst_name);
+		free(subst_name);
 		H5Fclose(fh);
 		return NULL;
 	}
+	free(subst_name);
 
 	sh = H5Dget_space(dh);
 	if ( sh < 0 ) {
@@ -880,221 +1115,6 @@ ImageFeatureList *image_hdf5_read_peaks_hdf5(const DataTemplate *dtempl,
 }
 
 
-struct parse_params {
-	hid_t fh;
-	int path_dim;
-	const char *path;
-	struct event *curr_event;
-	struct event_list *ev_list;
-	int top_level;
-};
-
-
-static herr_t parse_file_event_structure(hid_t loc_id, char *name,
-                                         const H5L_info_t *info,
-                                         struct parse_params *pp)
-
-{
-	char *substituted_path;
-	char *ph_loc;
-	char *truncated_path;
-	herr_t herrt_iterate, herrt_info;
-	struct H5O_info_t object_info;
-
-	if ( !pp->top_level ) {
-
-		int fail_push;
-
-		fail_push = push_path_entry_to_event(pp->curr_event, name);
-		if ( fail_push ) {
-			return -1;
-		}
-
-		substituted_path = event_path_placeholder_subst(name, pp->path);
-
-	} else {
-		substituted_path = strdup(pp->path);
-	}
-
-	if ( pp->top_level == 1 ) {
-		pp->top_level = 0;
-	}
-
-	truncated_path = strdup(substituted_path);
-	ph_loc = strstr(substituted_path,"%");
-	if ( ph_loc != NULL) {
-		truncated_path[ph_loc-substituted_path] = '\0';
-	}
-
-	herrt_iterate = 0;
-	herrt_info = 0;
-
-	herrt_info = H5Oget_info_by_name(pp->fh, truncated_path,
-                                 &object_info, H5P_DEFAULT);
-	if ( herrt_info < 0 ) {
-		free(truncated_path);
-		free(substituted_path);
-		return -1;
-	}
-
-	if ( pp->curr_event->path_length == pp->path_dim
-	 &&  object_info.type == H5O_TYPE_DATASET )
-	{
-
-		int fail_append;
-
-		fail_append = append_event_to_event_list(pp->ev_list,
-		                                         pp->curr_event);
-		if ( fail_append ) {
-			free(truncated_path);
-			free(substituted_path);
-			return -1;
-		}
-
-		pop_path_entry_from_event(pp->curr_event);
-		return 0;
-
-	} else {
-
-		pp->path = substituted_path;
-
-		if ( object_info.type == H5O_TYPE_GROUP ) {
-
-			herrt_iterate = H5Literate_by_name(pp->fh,
-			      truncated_path, H5_INDEX_NAME,
-			      H5_ITER_NATIVE, NULL,
-			      (H5L_iterate_t)parse_file_event_structure,
-			      (void *)pp, H5P_DEFAULT);
-		}
-	}
-
-	pop_path_entry_from_event(pp->curr_event);
-
-	free(truncated_path);
-	free(substituted_path);
-
-	return herrt_iterate;
-}
-
-
-static int fill_paths(hid_t fh, const DataTemplate *dtempl, int pi,
-                      struct event_list *master_el)
-{
-	struct parse_params pparams;
-	struct event *empty_event;
-	struct event_list *panel_ev_list;
-	int ei;
-	int check;
-
-	empty_event = initialize_event();
-	panel_ev_list = initialize_event_list();
-	if ( (empty_event == NULL) || (panel_ev_list == NULL) )
-	{
-		ERROR("Failed to allocate memory for event list.\n");
-		return 1;
-	}
-
-	pparams.path = dtempl->panels[pi].data;
-	pparams.fh = fh;
-	pparams.path_dim = dtempl->path_dim;
-	pparams.curr_event = empty_event;
-	pparams.top_level = 1;
-	pparams.ev_list = panel_ev_list;
-
-	check = parse_file_event_structure(fh, NULL, NULL, &pparams);
-	if ( check < 0 ) {
-		free_event(empty_event);
-		free_event_list(panel_ev_list);
-		return 1;
-	}
-
-	for ( ei=0; ei<panel_ev_list->num_events; ei++ ) {
-
-		int fail_add;
-
-		fail_add = add_non_existing_event_to_event_list(master_el,
-		                                     panel_ev_list->events[ei]);
-		if ( fail_add ) {
-			free_event(empty_event);
-			free_event_list(panel_ev_list);
-			return 1;
-		}
-
-	}
-
-	free_event(empty_event);
-	free_event_list(panel_ev_list);
-
-	return 0;
-}
-
-
-static int check_dims(hid_t fh, struct panel_template *p,
-                      struct event *ev,
-                      struct event_list *events, int *global_path_dim)
-{
-	char *full_panel_path;
-	hid_t dh;
-	hid_t sh;
-	int dims;
-	hsize_t *size;
-	hsize_t *max_size;
-	int hsdi;
-	int panel_path_dim = 0;
-	struct dim_structure *panel_dim_structure;
-
-	/* Get the full path for this panel in this event */
-	full_panel_path = retrieve_full_path(ev, p->data);
-
-	dh = H5Dopen2(fh, full_panel_path, H5P_DEFAULT);
-	if ( dh < 0 ) {
-		ERROR("Error opening '%s'\n", full_panel_path);
-		ERROR("Failed to enumerate events.  "
-		      "Check your geometry file.\n");
-		return 1;
-	}
-
-	sh = H5Dget_space(dh);
-	dims = H5Sget_simple_extent_ndims(sh);
-	size = malloc(dims*sizeof(hsize_t));
-	max_size = malloc(dims*sizeof(hsize_t));
-	if ( (size==NULL) || (max_size==NULL) ) {
-		ERROR("Failed to allocate memory for dimensions\n");
-		return 1;
-	}
-
-	dims = H5Sget_simple_extent_dims(sh, size, max_size);
-
-	panel_dim_structure = p->dim_structure;
-	for ( hsdi=0; hsdi<panel_dim_structure->num_dims; hsdi++ ) {
-		if ( panel_dim_structure->dims[hsdi] == HYSL_PLACEHOLDER ) {
-			panel_path_dim = size[hsdi];
-			break;
-		}
-	}
-
-	if ( *global_path_dim == -1 ) {
-
-		*global_path_dim = panel_path_dim;
-
-	} else if ( panel_path_dim != *global_path_dim ) {
-
-		ERROR("All panels must have the same number of frames\n");
-		ERROR("Panel %s has %i frames in one dimension, but the first "
-		      "panel has %i.\n",
-		      p->name, panel_path_dim, *global_path_dim);
-		free(size);
-		free(max_size);
-		return 1;
-	}
-
-	H5Sclose(sh);
-	H5Dclose(dh);
-
-	return 0;
-}
-
-
 struct event_list *image_hdf5_expand_frames(const DataTemplate *dtempl,
                                             const char *filename)
 {
@@ -1191,5 +1211,5 @@ struct event_list *image_hdf5_expand_frames(const DataTemplate *dtempl,
 
 int is_hdf5_file(const char *filename)
 {
-	return H5Fis_hdf5(filename);
+	return (H5Fis_hdf5(filename) > 0);
 }
diff --git a/libcrystfel/src/image-hdf5.h b/libcrystfel/src/image-hdf5.h
index 84a53d99..7a32a354 100644
--- a/libcrystfel/src/image-hdf5.h
+++ b/libcrystfel/src/image-hdf5.h
@@ -61,8 +61,9 @@ extern ImageFeatureList *image_hdf5_read_peaks_hdf5(const DataTemplate *dtempl,
                                                     const char *event,
                                                     int half_pixel_shift);
 
-extern struct event_list *image_hdf5_expand_frames(const DataTemplate *dtempl,
-                                                   const char *filename);
+extern char **image_hdf5_expand_frames(const DataTemplate *dtempl,
+                                       const char *filename,
+                                       int *n_frames);
 
 extern int is_hdf5_file(const char *filename);
 
diff --git a/libcrystfel/src/image.c b/libcrystfel/src/image.c
index 6eb6bb11..20e91e6d 100644
--- a/libcrystfel/src/image.c
+++ b/libcrystfel/src/image.c
@@ -287,12 +287,12 @@ static double get_value(struct image *image, const char *from)
 	val = strtod(from, &rval);
 	if ( (*rval == '\0') && (rval != from) ) return val;
 
-	if ( is_hdf5_file(image->filename) > 0 ) {
+	if ( is_hdf5_file(image->filename) ) {
 		return image_hdf5_get_value(from,
 		                            image->filename,
 		                            image->ev);
 
-	} else if ( is_cbf_file(image->filename) > 0 ) {
+	} else if ( is_cbf_file(image->filename) ) {
 		/* FIXME: From headers */
 		return NAN;
 
@@ -474,10 +474,10 @@ struct image *image_read(DataTemplate *dtempl, const char *filename,
 		return NULL;
 	}
 
-	if ( is_hdf5_file(filename) > 0 ) {
+	if ( is_hdf5_file(filename) ) {
 		image = image_hdf5_read(dtempl, filename, event);
 
-	} else if ( is_cbf_file(filename) > 0 ) {
+	} else if ( is_cbf_file(filename) ) {
 		image = image_cbf_read(dtempl, filename, event, 0);
 
 	} else if ( is_cbfgz_file(filename) ) {
@@ -545,13 +545,13 @@ struct image *image_read(DataTemplate *dtempl, const char *filename,
 			} else {
 				mask_fn = p->mask_file;
 			}
-			if ( is_hdf5_file(mask_fn) > 0 ) {
+			if ( is_hdf5_file(mask_fn) ) {
 				image_hdf5_read_mask(p, mask_fn, event,
 				                     image->bad[i],
 				                     dtempl->mask_good,
 				                     dtempl->mask_bad);
 
-			} else if ( is_cbf_file(filename) > 0 ) {
+			} else if ( is_cbf_file(filename) ) {
 				image_cbf_read_mask(p, mask_fn, event,
 				                    0, image->bad[i],
 				                    dtempl->mask_good,
@@ -645,7 +645,7 @@ ImageFeatureList *image_read_peaks(const DataTemplate *dtempl,
                                    const char *event,
                                    int half_pixel_shift)
 {
-	if ( is_hdf5_file(filename) > 0 ) {
+	if ( is_hdf5_file(filename) ) {
 
 		const char *ext;
 		ext = filename_extension(filename, NULL);
@@ -669,11 +669,16 @@ ImageFeatureList *image_read_peaks(const DataTemplate *dtempl,
 }
 
 
-struct event_list *image_expand_frames(const DataTemplate *dtempl,
-                                       const char *filename)
+char **image_expand_frames(const DataTemplate *dtempl,
+                           const char *filename, int *n_frames)
 {
-	/* FIXME: Dispatch to other versions, e.g. CBF files */
-	return image_hdf5_expand_frames(dtempl, filename);
+	if ( is_hdf5_file(filename) ) {
+		return image_hdf5_expand_frames(dtempl, filename,
+		                                n_frames);
+	} else {
+		ERROR("Can only expand HDF5 files\n");
+		return NULL;
+	}
 }
 
 
diff --git a/src/crystfel_gui.c b/src/crystfel_gui.c
index 87f57e7c..77a064f3 100644
--- a/src/crystfel_gui.c
+++ b/src/crystfel_gui.c
@@ -138,19 +138,21 @@ static void add_all_events(struct crystfelproject *proj,
                            const char *filename,
                            const DataTemplate *dtempl)
 {
-	struct event_list *events;
+	char **events;
 	int i;
+	int n_events;
 
-	events = image_expand_frames(dtempl, filename);
+	events = image_expand_frames(dtempl, filename, &n_events);
 	if ( events == NULL ) {
 		ERROR("Couldn't expand event list\n");
 		return;
 	}
 
-	for ( i=0; i<events->num_events; i++ ) {
-		add_file_to_project(proj, filename,
-		                    get_event_string(events->events[i]));
+	for ( i=0; i<n_events; i++ ) {
+		add_file_to_project(proj, filename, events[i]);
+		free(events[i]);
 	}
+	free(events);
 }
 
 
diff --git a/src/im-sandbox.c b/src/im-sandbox.c
index 753ceb82..d03a1f87 100644
--- a/src/im-sandbox.c
+++ b/src/im-sandbox.c
@@ -112,7 +112,8 @@ struct get_pattern_ctx
 	const DataTemplate *dtempl;
 	const char *prefix;
 	char *filename;
-	struct event_list *events;  /* FIXME: Deprecated */
+	char **events;
+	int n_events;
 	int event_index;
 };
 
@@ -184,11 +185,12 @@ static void check_hung_workers(struct sandbox *sb)
 }
 
 
-static char *read_prefixed_filename(struct get_pattern_ctx *gpctx, char **event)
+static char *read_prefixed_filename(struct get_pattern_ctx *gpctx,
+                                    char **event)
 {
 	char* line;
 
-	if ( event != NULL ) *event = NULL;
+	*event = NULL;
 
 	line = malloc(1024);
 	if ( line == NULL ) return NULL;
@@ -206,20 +208,18 @@ static char *read_prefixed_filename(struct get_pattern_ctx *gpctx, char **event)
 
 	} while ( line[0] == '\0' );
 
-	/* Chop off event ID if requested */
-	if ( event != NULL ) {
-		size_t n = strlen(line);
-		while ( line[n] != ' ' && n > 2 ) n--;
-		if ( n != 2 ) {
-			/* Event descriptor must contain "//".
-			* If it doesn't, assume the filename just contains a
-			* space. */
-			if ( strstr(&line[n], "//") != NULL ) {
-				line[n] = '\0';
-				*event = strdup(&line[n+1]);
-			}
-		} /* else no spaces at all */
-	}
+	/* Chop off event ID */
+	size_t n = strlen(line);
+	while ( line[n] != ' ' && n > 2 ) n--;
+	if ( n != 2 ) {
+		/* Event descriptor must contain "//".
+		 * If it doesn't, assume the filename just contains a
+		 * space. */
+		if ( strstr(&line[n], "//") != NULL ) {
+			line[n] = '\0';
+			*event = strdup(&line[n+1]);
+		}
+	} /* else no spaces at all */
 
 	if ( gpctx->use_basename ) {
 		char *tmp;
@@ -256,10 +256,10 @@ static int get_pattern(struct get_pattern_ctx *gpctx,
 
 	/* Is an event available already? */
 	if ( (gpctx->events != NULL)
-	  && (gpctx->event_index < gpctx->events->num_events) )
+	  && (gpctx->event_index < gpctx->n_events) )
 	{
-		*pfilename = strdup(gpctx->filename);
-		*pevent = get_event_string(gpctx->events->events[gpctx->event_index++]);
+		*pfilename = gpctx->filename;
+		*pevent = gpctx->events[gpctx->event_index++];
 		return 1;
 	}
 
@@ -272,13 +272,17 @@ static int get_pattern(struct get_pattern_ctx *gpctx,
 	/* Does the line from the input file contain an event ID?
 	 * If so, just send it straight back. */
 	if ( evstr != NULL ) {
-		*pfilename = strdup(filename);
-		*pevent = strdup(evstr);
+		*pfilename = filename;
+		*pevent = evstr;
 		return 1;
 	}
 
-	free_event_list(gpctx->events);
-	gpctx->events = image_expand_frames(gpctx->dtempl, filename);
+	/* We got a filename, but no event.  Attempt to expand... */
+	free(gpctx->events);  /* Free the old list.
+	                       * NB The actual strings were freed
+	                       * by fill_queue */
+	gpctx->events = image_expand_frames(gpctx->dtempl, filename,
+	                                    &gpctx->n_events);
 	if ( gpctx->events == NULL ) {
 		ERROR("Failed to get event list.\n");
 		return 0;
@@ -289,8 +293,8 @@ static int get_pattern(struct get_pattern_ctx *gpctx,
 	gpctx->filename = filename;
 
 	gpctx->event_index = 0;
-	*pfilename = strdup(gpctx->filename);
-	*pevent = get_event_string(gpctx->events->events[gpctx->event_index++]);
+	*pfilename = gpctx->filename;
+	*pevent = gpctx->events[gpctx->event_index++];
 	return 1;
 }
 
@@ -788,6 +792,7 @@ static int fill_queue(struct get_pattern_ctx *gpctx, struct sandbox *sb)
 		snprintf(sb->shared->queue[sb->shared->n_events++], MAX_EV_LEN,
 		         "%s %s %i", filename, evstr, sb->serial++);
 		sem_post(sb->queue_sem);
+		free(evstr);
 
 	}
 	return 0;
diff --git a/src/partialator.c b/src/partialator.c
index 11005555..1126095a 100644
--- a/src/partialator.c
+++ b/src/partialator.c
@@ -484,7 +484,7 @@ static struct custom_split *load_custom_split(const char *filename)
 			ds = bits[2];
 		} else {
 			fn = bits[0];
-			evs = get_event_string(NULL);
+			evs = strdup("(none)");
 			ds = bits[1];
 		}
 		free(bits);
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index f8de368c..78d39115 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -101,3 +101,39 @@ add_test(cellcompare_check cellcompare_check)
 add_executable(polarisation_check polarisation_check.c)
 target_include_directories(polarisation_check PRIVATE ${COMMON_INCLUDES})
 target_link_libraries(polarisation_check ${COMMON_LIBRARIES})
+add_test(polarisation_check polarisation_check)
+
+add_executable(evparse1 evparse1.c)
+target_include_directories(evparse1 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse1 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse1 evparse1)
+
+add_executable(evparse2 evparse2.c)
+target_include_directories(evparse2 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse2 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse2 evparse2)
+
+add_executable(evparse3 evparse3.c)
+target_include_directories(evparse3 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse3 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse3 evparse3)
+
+add_executable(evparse4 evparse4.c)
+target_include_directories(evparse4 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse4 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse4 evparse4)
+
+add_executable(evparse5 evparse5.c)
+target_include_directories(evparse5 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse5 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse5 evparse5)
+
+add_executable(evparse6 evparse6.c)
+target_include_directories(evparse6 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse6 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse6 evparse6)
+
+add_executable(evparse7 evparse7.c)
+target_include_directories(evparse7 PRIVATE ${COMMON_INCLUDES})
+target_link_libraries(evparse7 ${COMMON_LIBRARIES} -lhdf5)
+add_test(evparse7 evparse7)
diff --git a/tests/evparse1.c b/tests/evparse1.c
new file mode 100644
index 00000000..ad037841
--- /dev/null
+++ b/tests/evparse1.c
@@ -0,0 +1,73 @@
+/*
+ * evparse1.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	char **plvals;
+	int n_plvals;
+	int r = 0;
+
+	plvals = read_path_parts("cc/data123/bb//234/59", &n_plvals);
+
+	if ( plvals == NULL ) {
+		printf("read_path_parts failed\n");
+		r++;
+	}
+
+	if ( n_plvals != 3 ) {
+		printf("Wrong number of path parts\n");
+		r++;
+	}
+
+	if ( plvals == NULL ) return r;
+
+	if ( strcmp(plvals[0], "cc") != 0 ) {
+		printf("First path part is wrong\n");
+		r++;
+	}
+	if ( strcmp(plvals[1], "data123") != 0 ) {
+		printf("Second path part is wrong\n");
+		r++;
+	}
+	if ( strcmp(plvals[2], "bb") != 0 ) {
+		printf("Third path part is wrong\n");
+		r++;
+	}
+
+	return r;
+}
diff --git a/tests/evparse2.c b/tests/evparse2.c
new file mode 100644
index 00000000..1499b13b
--- /dev/null
+++ b/tests/evparse2.c
@@ -0,0 +1,65 @@
+/*
+ * evparse2.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	char **plvals;
+	int n_plvals;
+	int r = 0;
+
+	plvals = read_path_parts("bb//234/59", &n_plvals);
+
+	if ( plvals == NULL ) {
+		printf("read_path_parts failed\n");
+		r++;
+	}
+
+	if ( n_plvals != 1 ) {
+		printf("Wrong number of path parts\n");
+		r++;
+	}
+
+	if ( plvals == NULL ) return r;
+
+	if ( strcmp(plvals[0], "bb") != 0 ) {
+		printf("First path part is wrong\n");
+		r++;
+	}
+
+	return r;
+}
diff --git a/tests/evparse3.c b/tests/evparse3.c
new file mode 100644
index 00000000..ef6733d0
--- /dev/null
+++ b/tests/evparse3.c
@@ -0,0 +1,58 @@
+/*
+ * evparse3.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	char **plvals;
+	int n_plvals;
+	int r = 0;
+
+	plvals = read_path_parts("//234/59", &n_plvals);
+
+	if ( plvals == NULL ) {
+		printf("read_path_parts failed\n");
+		r++;
+	}
+
+	if ( n_plvals != 0 ) {
+		printf("Wrong number of path parts\n");
+		r++;
+	}
+
+	return r;
+}
diff --git a/tests/evparse4.c b/tests/evparse4.c
new file mode 100644
index 00000000..ca28fa24
--- /dev/null
+++ b/tests/evparse4.c
@@ -0,0 +1,68 @@
+/*
+ * evparse4.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	int *dvals;
+	int n_dvals = 99;
+	int r = 0;
+
+	dvals = read_dim_parts("cc/data123/bb//234/59", &n_dvals);
+
+	if ( n_dvals != 2 ) {
+		printf("Wrong number of dimension parts\n");
+		r++;
+	}
+
+	if ( dvals == NULL ) {
+		printf("read_dim_parts failed\n");
+		return 1;
+	}
+
+	if ( dvals[0] != 234 ) {
+		printf("First dimension part is wrong\n");
+		r++;
+	}
+	if ( dvals[1] != 59 ) {
+		printf("Second dimension part is wrong "
+		       "(%i, should be %i)\n", dvals[1], 59);
+		r++;
+	}
+
+	return r;
+}
diff --git a/tests/evparse5.c b/tests/evparse5.c
new file mode 100644
index 00000000..ed0d9b85
--- /dev/null
+++ b/tests/evparse5.c
@@ -0,0 +1,64 @@
+/*
+ * evparse5.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	int *dvals;
+	int n_dvals = 99;
+	int r = 0;
+
+	dvals = read_dim_parts("cc/data123/bb//59", &n_dvals);
+
+	if ( n_dvals != 1 ) {
+		printf("Wrong number of dimension parts\n");
+		r++;
+	}
+
+	if ( dvals == NULL ) {
+		printf("read_dim_parts failed\n");
+		return 1;
+	}
+
+	if ( dvals[0] != 59 ) {
+		printf("First dimension part is wrong "
+		       "(%i, should be %i)\n", dvals[0], 59);
+		r++;
+	}
+
+	return r;
+}
diff --git a/tests/evparse6.c b/tests/evparse6.c
new file mode 100644
index 00000000..235c6204
--- /dev/null
+++ b/tests/evparse6.c
@@ -0,0 +1,59 @@
+/*
+ * evparse6.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	int *dvals;
+	int n_dvals = 99;
+	int r = 0;
+
+	dvals = read_dim_parts("cc/data123/bb//", &n_dvals);
+
+	if ( n_dvals != 0 ) {
+		printf("Wrong number of dimension parts (got %i)\n",
+		       n_dvals);
+		r++;
+	}
+
+	if ( dvals == NULL ) {
+		printf("read_dim_parts failed\n");
+		return 1;
+	}
+
+	return r;
+}
diff --git a/tests/evparse7.c b/tests/evparse7.c
new file mode 100644
index 00000000..7e7ff104
--- /dev/null
+++ b/tests/evparse7.c
@@ -0,0 +1,57 @@
+/*
+ * evparse7.c
+ *
+ * Check that event string parsing works
+ *
+ * Copyright © 2020 Deutsches Elektronen-Synchrotron DESY,
+ *                  a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2020 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "../libcrystfel/src/image-hdf5.c"
+
+int main(int argc, char *argv[])
+{
+	char *subs;
+
+	subs = substitute_path("cc/data123/bb//234/59",
+	                       "/data/%/test/%/%");
+
+	if ( subs == NULL ) {
+		printf("substitute_path() failed\n");
+		return 1;
+	}
+
+	if ( strcmp(subs, "/data/cc/test/data123/bb") != 0 ) {
+		printf("Wrong substitution: got '%s'\n", subs);
+		return 1;
+	}
+
+	return 0;
+}