parsing: use string references for font family and drawing text

That eliminates most uses of strdup() in the rendering process.

9 files changed, 77 insertions, 76 deletions

diff --git a/libass/ass_cache.c b/libass/ass_cache.c
index d0dd6fb..70c0113 100644
--- a/libass/ass_cache.c
+++ b/libass/ass_cache.c
@@ -40,12 +40,13 @@
 // font cache
 static bool font_key_move(void *dst, void *src)
 {
-    ASS_FontDesc *k = src;
-    if (dst)
-        memcpy(dst, src, sizeof(ASS_FontDesc));
-    else
-        free(k->family);
-    return true;
+    if (!dst)
+        return true;
+
+    ASS_FontDesc *d = dst, *s = dst;
+    memcpy(dst, src, sizeof(ASS_FontDesc));
+    d->family.str = ass_copy_string(s->family);
+    return d->family.str;
 }
 
 static void font_destruct(void *key, void *value)
@@ -207,8 +208,8 @@ static bool outline_key_move(void *dst, void *src)
     }
     memcpy(dst, src, sizeof(OutlineHashKey));
     if (s->type == OUTLINE_DRAWING) {
-        d->u.drawing.text = strdup(s->u.drawing.text);
-        return d->u.drawing.text;
+        d->u.drawing.text.str = ass_copy_string(s->u.drawing.text);
+        return d->u.drawing.text.str;
     }
     if (s->type == OUTLINE_BORDER)
         ass_cache_inc_ref(s->u.border.outline);
@@ -226,7 +227,7 @@ static void outline_destruct(void *key, void *value)
         ass_cache_dec_ref(k->u.glyph.font);
         break;
     case OUTLINE_DRAWING:
-        free(k->u.drawing.text);
+        free((char *) k->u.drawing.text.str);
         break;
     case OUTLINE_BORDER:
         ass_cache_dec_ref(k->u.border.outline);
diff --git a/libass/ass_cache_template.h b/libass/ass_cache_template.h
index 80515c2..3328d44 100644
--- a/libass/ass_cache_template.h
+++ b/libass/ass_cache_template.h
@@ -5,7 +5,7 @@
 #define GENERIC(type, member) \
         type member;
 #define STRING(member) \
-        char *member;
+        ASS_StringView member;
 #define VECTOR(member) \
         ASS_Vector member;
 #define END(typedefnamename) \
@@ -22,7 +22,7 @@
 #define GENERIC(type, member) \
             a->member == b->member &&
 #define STRING(member) \
-            strcmp(a->member, b->member) == 0 &&
+            ass_string_equal(a->member, b->member) &&
 #define VECTOR(member) \
             a->member.x == b->member.x && a->member.y == b->member.y &&
 #define END(typedefname) \
@@ -38,7 +38,7 @@
 #define GENERIC(type, member) \
         hval = fnv_32a_buf(&p->member, sizeof(p->member), hval);
 #define STRING(member) \
-        hval = fnv_32a_str(p->member, hval);
+        hval = fnv_32a_buf(p->member.str, p->member.len, hval);
 #define VECTOR(member) GENERIC(, member.x); GENERIC(, member.y);
 #define END(typedefname) \
         return hval; \
diff --git a/libass/ass_font.c b/libass/ass_font.c
index 29ee877..7d79d2e 100644
--- a/libass/ass_font.c
+++ b/libass/ass_font.c
@@ -588,5 +588,5 @@ void ass_font_clear(ASS_Font *font)
         if (font->faces[i])
             FT_Done_Face(font->faces[i]);
     }
-    free(font->desc.family);
+    free((char *) font->desc.family.str);
 }
diff --git a/libass/ass_fontselect.c b/libass/ass_fontselect.c
index d360e1c..3bf034b 100644
--- a/libass/ass_fontselect.c
+++ b/libass/ass_fontselect.c
@@ -692,7 +692,7 @@ char *ass_font_select(ASS_FontSelector *priv, ASS_Library *library,
                       int *uid, ASS_FontStream *data, uint32_t code)
 {
     char *res = 0;
-    const char *family = font->desc.family;
+    const char *family = font->desc.family.str;  // always zero-terminated
     unsigned bold = font->desc.bold;
     unsigned italic = font->desc.italic;
     ASS_FontProvider *default_provider = priv->default_provider;
diff --git a/libass/ass_parse.c b/libass/ass_parse.c
index 2e35e2b..8ba39c8 100644
--- a/libass/ass_parse.c
+++ b/libass/ass_parse.c
@@ -102,17 +102,16 @@ void update_font(ASS_Renderer *render_priv)
     unsigned val;
     ASS_FontDesc desc;
 
-    if (!render_priv->state.family)
+    desc.family = render_priv->state.family;
+    if (!desc.family.str)
         return;
-    if (render_priv->state.family[0] == '@') {
+    if (desc.family.len && desc.family.str[0] == '@') {
         desc.vertical = 1;
-        desc.family = strdup(render_priv->state.family + 1);
+        desc.family.str++;
+        desc.family.len--;
     } else {
         desc.vertical = 0;
-        desc.family = strdup(render_priv->state.family);
     }
-    if (!desc.family)
-        return;
 
     val = render_priv->state.bold;
     // 0 = normal, 1 = bold, >1 = exact weight
@@ -234,7 +233,8 @@ static bool parse_vector_clip(ASS_Renderer *render_priv,
         scale = argtoi(args[0]);
 
     struct arg text = args[nargs - 1];
-    render_priv->state.clip_drawing_text = strndup(text.start, text.end - text.start);
+    render_priv->state.clip_drawing_text.str = text.start;
+    render_priv->state.clip_drawing_text.len = text.end - text.start;
     render_priv->state.clip_drawing_scale = scale;
     return true;
 }
@@ -381,7 +381,7 @@ char *parse_tags(ASS_Renderer *render_priv, char *p, char *end, double pwr,
                 render_priv->state.clip_y1 =
                     render_priv->state.clip_y1 * (1 - pwr) + y1 * pwr;
                 render_priv->state.clip_mode = 1;
-            } else if (!render_priv->state.clip_drawing_text) {
+            } else if (!render_priv->state.clip_drawing_text.str) {
                 if (parse_vector_clip(render_priv, args, nargs))
                     render_priv->state.clip_drawing_mode = 1;
             }
@@ -517,19 +517,16 @@ char *parse_tags(ASS_Renderer *render_priv, char *p, char *end, double pwr,
                 render_priv->state.frz =
                     render_priv->state.style->Angle;
         } else if (tag("fn")) {
-            char *family;
             char *start = args->start;
             if (nargs && strncmp(start, "0", args->end - start)) {
                 skip_spaces(&start);
-                family = strndup(start, args->end - start);
+                render_priv->state.family.str = start;
+                render_priv->state.family.len = args->end - start;
             } else {
-                family = strdup(render_priv->state.style->FontName);
-            }
-            if (family) {
-                free(render_priv->state.family);
-                render_priv->state.family = family;
-                update_font(render_priv);
+                render_priv->state.family.str = render_priv->state.style->FontName;
+                render_priv->state.family.len = strlen(render_priv->state.style->FontName);
             }
+            update_font(render_priv);
         } else if (tag("alpha")) {
             int i;
             if (nargs) {
@@ -708,7 +705,7 @@ char *parse_tags(ASS_Renderer *render_priv, char *p, char *end, double pwr,
                 render_priv->state.clip_y1 =
                     render_priv->state.clip_y1 * (1 - pwr) + y1 * pwr;
                 render_priv->state.clip_mode = 0;
-            } else if (!render_priv->state.clip_drawing_text) {
+            } else if (!render_priv->state.clip_drawing_text.str) {
                 if (parse_vector_clip(render_priv, args, nargs))
                     render_priv->state.clip_drawing_mode = 0;
             }
diff --git a/libass/ass_render.c b/libass/ass_render.c
index 56ed2f3..1962702 100644
--- a/libass/ass_render.c
+++ b/libass/ass_render.c
@@ -644,7 +644,7 @@ static inline size_t bitmap_size(const Bitmap *bm)
  */
 static void blend_vector_clip(ASS_Renderer *render_priv, ASS_Image *head)
 {
-    if (!render_priv->state.clip_drawing_text)
+    if (!render_priv->state.clip_drawing_text.str)
         return;
 
     OutlineHashKey ol_key;
@@ -998,13 +998,9 @@ void reset_render_context(ASS_Renderer *render_priv, ASS_Style *style)
         (style->StrikeOut ? DECO_STRIKETHROUGH : 0);
     render_priv->state.font_size = style->FontSize;
 
-    char* new_family = strdup(style->FontName);
-    if (new_family) {
-        free(render_priv->state.family);
-        render_priv->state.family = new_family;
-        render_priv->state.treat_family_as_pattern =
-            style->treat_fontname_as_pattern;
-    }
+    render_priv->state.family.str = style->FontName;
+    render_priv->state.family.len = strlen(style->FontName);
+    render_priv->state.treat_family_as_pattern = style->treat_fontname_as_pattern;
     render_priv->state.bold = style->Bold;
     render_priv->state.italic = style->Italic;
     update_font(render_priv);
@@ -1067,17 +1063,14 @@ init_render_context(ASS_Renderer *render_priv, ASS_Event *event)
 static void free_render_context(ASS_Renderer *render_priv)
 {
     ass_cache_dec_ref(render_priv->state.font);
-    free(render_priv->state.family);
-    free(render_priv->state.clip_drawing_text);
 
     render_priv->state.font = NULL;
-    render_priv->state.family = NULL;
-    render_priv->state.clip_drawing_text = NULL;
+    render_priv->state.family.str = NULL;
+    render_priv->state.family.len = 0;
+    render_priv->state.clip_drawing_text.str = NULL;
+    render_priv->state.clip_drawing_text.len = 0;
 
-    TextInfo *text_info = &render_priv->text_info;
-    for (int n = 0; n < text_info->length; n++)
-        free(text_info->glyphs[n].drawing_text);
-    text_info->length = 0;
+    render_priv->text_info.length = 0;
 }
 
 /**
@@ -1095,7 +1088,7 @@ get_outline_glyph(ASS_Renderer *priv, GlyphInfo *info)
 
     int32_t asc, desc;
     OutlineHashKey key;
-    if (info->drawing_text) {
+    if (info->drawing_text.str) {
         key.type = OUTLINE_DRAWING;
         key.u.drawing.text = info->drawing_text;
         val = ass_cache_get(priv->cache.outline_cache, &key, priv);
@@ -1143,7 +1136,7 @@ get_outline_glyph(ASS_Renderer *priv, GlyphInfo *info)
     info->bbox.x_max = lrint(val->cbox.x_max * scale.x + offset.x);
     info->bbox.y_max = lrint(val->cbox.y_max * scale.y + offset.y);
 
-    if (info->drawing_text || priv->settings.shaper == ASS_SHAPING_SIMPLE) {
+    if (info->drawing_text.str || priv->settings.shaper == ASS_SHAPING_SIMPLE) {
         info->cluster_advance.x = info->advance.x = lrint(val->advance * scale.x);
         info->cluster_advance.y = info->advance.y = 0;
     }
@@ -1180,7 +1173,7 @@ size_t ass_outline_construct(void *key, void *value, void *priv)
     case OUTLINE_DRAWING:
         {
             ASS_Rect bbox;
-            const char *text = outline_key->u.drawing.text;
+            const char *text = outline_key->u.drawing.text.str;  // always zero-terminated
             if (!ass_drawing_parse(&v->outline[0], &bbox, text, render_priv->library))
                 return 1;
 
@@ -1874,9 +1867,9 @@ static void split_style_runs(ASS_Renderer *render_priv)
         info->starts_new_run =
             info->effect_timing ||  // but ignore effect_skip_timing
             (effect_type != EF_NONE && effect_type != last_effect_type) ||
-            info->drawing_text ||
-            last->drawing_text ||
-            strcmp(last->font->desc.family, info->font->desc.family) ||
+            info->drawing_text.str ||
+            last->drawing_text.str ||
+            !ass_string_equal(last->font->desc.family, info->font->desc.family) ||
             last->font->desc.vertical != info->font->desc.vertical ||
             last->font_size != info->font_size ||
             last->c[0] != info->c[0] ||
@@ -1913,11 +1906,10 @@ static bool parse_events(ASS_Renderer *render_priv, ASS_Event *event)
     TextInfo *text_info = &render_priv->text_info;
 
     char *p = event->Text, *q;
-    char *drawing_text;
 
     // Event parsing.
     while (true) {
-        drawing_text = NULL;
+        ASS_StringView drawing_text = {NULL, 0};
 
         // get next char, executing style override
         // this affects render_context
@@ -1933,7 +1925,8 @@ static bool parse_events(ASS_Renderer *render_priv, ASS_Event *event)
                     q++;
                 while ((*q != '{') && (*q != 0))
                     q++;
-                drawing_text = strndup(p, q - p);
+                drawing_text.str = p;
+                drawing_text.len = q - p;
                 code = 0xfffc; // object replacement character
                 p = q;
                 break;
@@ -1966,7 +1959,7 @@ static bool parse_events(ASS_Renderer *render_priv, ASS_Event *event)
         memset(info, 0, sizeof(GlyphInfo));
 
         // Parse drawing
-        if (drawing_text) {
+        if (drawing_text.str) {
             info->drawing_text = drawing_text;
             info->drawing_scale = render_priv->state.drawing_scale;
             info->drawing_pbo = render_priv->state.pbo;
@@ -1975,7 +1968,7 @@ static bool parse_events(ASS_Renderer *render_priv, ASS_Event *event)
         // Fill glyph information
         info->symbol = code;
         info->font = render_priv->state.font;
-        if (!drawing_text)
+        if (!drawing_text.str)
             ass_cache_inc_ref(info->font);
         for (int i = 0; i < 4; i++) {
             uint32_t clr = render_priv->state.c[i];
@@ -2018,7 +2011,7 @@ static bool parse_events(ASS_Renderer *render_priv, ASS_Event *event)
                 render_priv->font_scale * info->scale_x);
         info->scale_fix = 1;
 
-        if (!drawing_text)
+        if (!drawing_text.str)
             fix_glyph_scaling(render_priv, info);
 
         text_info->length++;
@@ -2032,7 +2025,6 @@ static bool parse_events(ASS_Renderer *render_priv, ASS_Event *event)
 
 fail:
     free_render_context(render_priv);
-    free(drawing_text);
     return false;
 }
 
diff --git a/libass/ass_render.h b/libass/ass_render.h
index 43a7185..18d87ba 100644
--- a/libass/ass_render.h
+++ b/libass/ass_render.h
@@ -131,7 +131,7 @@ typedef struct glyph_info {
     int glyph_index;
     hb_script_t script;
     double font_size;
-    char *drawing_text;
+    ASS_StringView drawing_text;
     int drawing_scale;
     int drawing_pbo;
     OutlineHashValue *outline;
@@ -239,7 +239,7 @@ typedef struct {
     double shadow_x;
     double shadow_y;
     double pbo;                 // drawing baseline offset
-    char *clip_drawing_text;
+    ASS_StringView clip_drawing_text;
 
     // used to store RenderContext.style when doing selective style overrides
     ASS_Style override_style_temp_storage;
@@ -262,7 +262,7 @@ typedef struct {
     int scroll_y0, scroll_y1;
 
     // face properties
-    char *family;
+    ASS_StringView family;
     unsigned bold;
     unsigned italic;
     int treat_family_as_pattern;
diff --git a/libass/ass_shaper.c b/libass/ass_shaper.c
index 41392c6..4665e7a 100644
--- a/libass/ass_shaper.c
+++ b/libass/ass_shaper.c
@@ -665,7 +665,7 @@ static bool shape_harfbuzz(ASS_Shaper *shaper, GlyphInfo *glyphs, size_t len)
         glyphs[i].skip = true;
 
     for (i = 0; i < len; i++) {
-        if (glyphs[i].drawing_text) {
+        if (glyphs[i].drawing_text.str) {
             glyphs[i].skip = false;
             continue;
         }
@@ -805,7 +805,7 @@ void ass_shaper_find_runs(ASS_Shaper *shaper, ASS_Renderer *render_priv,
     // find appropriate fonts for the shape runs
     for (i = 0; i < len; i++) {
         GlyphInfo *info = glyphs + i;
-        if (!info->drawing_text) {
+        if (!info->drawing_text.str) {
             // set size and get glyph index
             ass_font_get_index(render_priv->fontselect, info->font,
                     info->symbol, &info->face_index, &info->glyph_index);
diff --git a/libass/ass_utils.h b/libass/ass_utils.h
index 1108c90..3f65b87 100644
--- a/libass/ass_utils.h
+++ b/libass/ass_utils.h
@@ -52,6 +52,26 @@ int has_avx(void);
 int has_avx2(void);
 #endif
 
+typedef struct {
+    const char *str;
+    size_t len;
+} ASS_StringView;
+
+static inline char *ass_copy_string(ASS_StringView src)
+{
+    char *buf = malloc(src.len + 1);
+    if (buf) {
+        memcpy(buf, src.str, src.len);
+        buf[src.len] = '\0';
+    }
+    return buf;
+}
+
+static inline bool ass_string_equal(ASS_StringView str1, ASS_StringView str2)
+{
+    return str1.len == str2.len && !memcmp(str1.str, str2.str, str1.len);
+}
+
 #ifndef HAVE_STRNDUP
 char *ass_strndup(const char *s, size_t n);
 #define strndup ass_strndup
@@ -163,9 +183,9 @@ static inline int double_to_d22(double x)
 #define FNV1_32A_INIT 0x811c9dc5U
 #define FNV1_32A_PRIME 16777619U
 
-static inline uint32_t fnv_32a_buf(void *buf, size_t len, uint32_t hval)
+static inline uint32_t fnv_32a_buf(const void *buf, size_t len, uint32_t hval)
 {
-    unsigned char *bp = (unsigned char *) buf;
+    const uint8_t *bp = buf;
     size_t n = (len + 3) / 4;
 
     switch (len % 4) {
@@ -178,15 +198,6 @@ static inline uint32_t fnv_32a_buf(void *buf, size_t len, uint32_t hval)
 
     return hval;
 }
-static inline uint32_t fnv_32a_str(const char *str, uint32_t hval)
-{
-    unsigned char *s = (unsigned char *) str;
-    while (*s) {
-        hval ^= *s++;
-        hval *= FNV1_32A_PRIME;
-    }
-    return hval;
-}
 
 static inline int mystrtoi(char **p, int *res)
 {