Auto merge of #6937 - mbrubeck:hb_funcs, r=glennw

Store Harfbuzz callback functions in a static var

r? gw

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components/gfx/Cargo.toml

@@ -8,6 +8,22 @@ authors = ["The Servo Project Developers"]
 name = "gfx"
 path = "lib.rs"
 
+[dependencies]
+bitflags = "0.3"
+euclid = "0.1"
+fnv = "1.0"
+harfbuzz = "0.1"
+lazy_static = "0.1"
+libc = "0.1"
+log = "0.3"
+rand = "0.3"
+rustc-serialize = "0.3"
+serde = "0.4"
+serde_macros = "0.4"
+smallvec = "0.1"
+string_cache = "0.1"
+time = "0.1.12"
+
 [dependencies.plugins]
 path = "../plugins"
 
@@ -51,21 +67,6 @@ git = "https://github.com/pcwalton/ipc-channel"
 version = "0.2"
 features = [ "serde_serialization" ]
 
-[dependencies]
-log = "0.3"
-fnv = "1.0"
-time = "0.1.12"
-bitflags = "0.3"
-rustc-serialize = "0.3"
-libc = "0.1"
-rand = "0.3"
-harfbuzz = "0.1"
-smallvec = "0.1"
-string_cache = "0.1"
-euclid = "0.1"
-serde = "0.4"
-serde_macros = "0.4"
-
 [target.x86_64-apple-darwin.dependencies]
 core-foundation = "0.1"
 core-graphics = "0.1"

components/gfx/lib.rs

@@ -12,6 +12,7 @@
 #![feature(mpsc_select)]
 #![feature(plugin)]
 #![feature(str_char)]
+#![feature(unique)]
 #![feature(vec_push_all)]
 
 #![plugin(plugins)]
@@ -26,6 +27,8 @@ extern crate azure;
 extern crate fnv;
 extern crate euclid;
 extern crate ipc_channel;
+#[macro_use]
+extern crate lazy_static;
 extern crate layers;
 extern crate libc;
 #[macro_use]

components/gfx/text/shaping/harfbuzz.rs

@@ -149,7 +149,6 @@ struct FontAndShapingOptions {
 pub struct Shaper {
     hb_face: *mut hb_face_t,
     hb_font: *mut hb_font_t,
-    hb_funcs: *mut hb_font_funcs_t,
     font_and_shaping_options: Box<FontAndShapingOptions>,
 }
 
@@ -161,9 +160,6 @@ impl Drop for Shaper {
 
             assert!(!self.hb_font.is_null());
             RUST_hb_font_destroy(self.hb_font);
-
-            assert!(!self.hb_funcs.is_null());
-            RUST_hb_font_funcs_destroy(self.hb_funcs);
         }
     }
 }
@@ -193,18 +189,11 @@ impl Shaper {
                                    Shaper::float_to_fixed(pt_size) as c_int);
 
             // configure static function callbacks.
-            // NB. This funcs structure could be reused globally, as it never changes.
-            let hb_funcs: *mut hb_font_funcs_t = RUST_hb_font_funcs_create();
-            RUST_hb_font_funcs_set_glyph_func(hb_funcs, glyph_func, ptr::null_mut(), None);
-            RUST_hb_font_funcs_set_glyph_h_advance_func(hb_funcs, glyph_h_advance_func, ptr::null_mut(), None);
-            RUST_hb_font_funcs_set_glyph_h_kerning_func(
-                hb_funcs, glyph_h_kerning_func, ptr::null_mut(), ptr::null_mut());
-            RUST_hb_font_set_funcs(hb_font, hb_funcs, font as *mut Font as *mut c_void, None);
+            RUST_hb_font_set_funcs(hb_font, **HB_FONT_FUNCS, font as *mut Font as *mut c_void, None);
 
             Shaper {
                 hb_face: hb_face,
                 hb_font: hb_font,
-                hb_funcs: hb_funcs,
                 font_and_shaping_options: font_and_shaping_options,
             }
         }
@@ -536,7 +525,20 @@ impl Shaper {
     }
 }
 
-/// Callbacks from Harfbuzz when font map and glyph advance lookup needed.
+// Callbacks from Harfbuzz when font map and glyph advance lookup needed.
+lazy_static! {
+    static ref HB_FONT_FUNCS: ptr::Unique<hb_font_funcs_t> = unsafe {
+        let hb_funcs = RUST_hb_font_funcs_create();
+        RUST_hb_font_funcs_set_glyph_func(hb_funcs, glyph_func, ptr::null_mut(), None);
+        RUST_hb_font_funcs_set_glyph_h_advance_func(
+            hb_funcs, glyph_h_advance_func, ptr::null_mut(), None);
+        RUST_hb_font_funcs_set_glyph_h_kerning_func(
+            hb_funcs, glyph_h_kerning_func, ptr::null_mut(), ptr::null_mut());
+
+        ptr::Unique::new(hb_funcs)
+    };
+}
+
 extern fn glyph_func(_: *mut hb_font_t,
                      font_data: *mut c_void,
                      unicode: hb_codepoint_t,

components/servo/Cargo.lock

@@ -466,6 +466,7 @@ dependencies = [
  "harfbuzz 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.1.0 (git+https://github.com/pcwalton/ipc-channel)",
  "layers 0.1.0 (git+https://github.com/servo/rust-layers)",
+ "lazy_static 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",