From 241d96e57c965f454410f4b36b05c28184170f65 Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Wed, 5 Nov 2014 14:37:54 -0800
Subject: [PATCH] Save a few more bytes per geometry in the temporary file

by using bytes instead of ints for the drawing operations
---
 geojson.c   | 16 +++++++++++++---
 geometry.cc |  2 +-
 geometry.hh |  2 +-
 tile.h      |  1 +
 4 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/geojson.c b/geojson.c
index 3f15c15..ff498f6 100644
--- a/geojson.c
+++ b/geojson.c
@@ -96,6 +96,11 @@ void serialize_int(FILE *out, int n, long long *fpos, char *fname, json_pull *so
 	*fpos += sizeof(int);
 }
 
+void serialize_byte(FILE *out, signed char n, long long *fpos, char *fname, json_pull *source) {
+	fwrite_check(&n, sizeof(signed char), 1, out, fname, source);
+	*fpos += sizeof(signed char);
+}
+
 void serialize_uint(FILE *out, unsigned n, long long *fpos, char *fname, json_pull *source) {
 	fwrite_check(&n, sizeof(unsigned), 1, out, fname, source);
 	*fpos += sizeof(unsigned);
@@ -153,7 +158,7 @@ void parse_geometry(int t, json_object *j, unsigned *bbox, long long *fpos, FILE
 				}
 			}
 
-			serialize_int(out, op, fpos, fname, source);
+			serialize_byte(out, op, fpos, fname, source);
 			serialize_uint(out, x, fpos, fname, source);
 			serialize_uint(out, y, fpos, fname, source);
 		} else {
@@ -163,7 +168,7 @@ void parse_geometry(int t, json_object *j, unsigned *bbox, long long *fpos, FILE
 
 	if (t == GEOM_POLYGON) {
 		if (*fpos != began) {
-			serialize_int(out, VT_CLOSEPATH, fpos, fname, source);
+			serialize_byte(out, VT_CLOSEPATH, fpos, fname, source);
 		}
 	}
 }
@@ -173,6 +178,11 @@ void deserialize_int(char **f, int *n) {
 	*f += sizeof(int);
 }
 
+void deserialize_byte(char **f, signed char *n) {
+	memcpy(n, *f, sizeof(signed char));
+	*f += sizeof(signed char);
+}
+
 struct pool_val *deserialize_string(char **f, struct pool *p, int type) {
 	struct pool_val *ret;
 	int len;
@@ -382,7 +392,7 @@ void read_json(FILE *f, char *fname, char *layername, int maxzoom, int minzoom,
 			unsigned bbox[] = { UINT_MAX, UINT_MAX, 0, 0 };
 
 			parse_geometry(t, coordinates, bbox, &fpos, metafile, VT_MOVETO, fname, jp);
-			serialize_int(metafile, VT_END, &fpos, fname, jp);
+			serialize_byte(metafile, VT_END, &fpos, fname, jp);
 
 			char *metakey[properties->length];
 			char *metaval[properties->length];
diff --git a/geometry.cc b/geometry.cc
index 31eef53..5425d94 100644
--- a/geometry.cc
+++ b/geometry.cc
@@ -22,7 +22,7 @@ drawvec decode_geometry(char **meta, int z, unsigned tx, unsigned ty, int detail
 	while (1) {
 		draw d;
 
-		deserialize_int(meta, &d.op);
+		deserialize_byte(meta, &d.op);
 		if (d.op == VT_END) {
 			break;
 		}
diff --git a/geometry.hh b/geometry.hh
index b21bb99..7af9b4e 100644
--- a/geometry.hh
+++ b/geometry.hh
@@ -1,5 +1,5 @@
 struct draw {
-	int op;
+	signed char op;
 	long long x;
 	long long y;
 	int necessary;
diff --git a/tile.h b/tile.h
index 9b29f8b..2141590 100644
--- a/tile.h
+++ b/tile.h
@@ -14,6 +14,7 @@
 struct pool;
 
 void deserialize_int(char **f, int *n);
+void deserialize_byte(char **f, signed char *n);
 struct pool_val *deserialize_string(char **f, struct pool *p, int type);