Rework handling of PDF names for speed and memory.

Currently, every PDF name is allocated in a pdf_obj structure, and
comparisons are done using strcmp. Given that we can predict most
of the PDF names we'll use in a given file, this seems wasteful.

The pdf_obj type is opaque outside the pdf-object.c file, so we can
abuse it slightly without anyone outside knowing.

We collect a sorted list of names used in PDF (resources/pdf/names.txt),
and we add a utility (namedump) that preprocesses this into 2 header
files.

The first (include/mupdf/pdf/pdf-names-table.h, included as part of
include/mupdf/pdf/object.h), defines a set of "PDF_NAME_xxxx"
entries. These are pdf_obj *'s that callers can use to mean "A PDF
object that means literal name 'xxxx'"

The second (source/pdf/pdf-name-impl.h) is a C array of names.

We therefore update the code so that rather than passing "xxxx" to
functions (such as pdf_dict_gets(...)) we now pass PDF_NAME_xxxx (to
pdf_dict_get(...)). This is a fairly natural (if widespread) change.

The pdf_dict_getp (and sibling) functions that take a path (e.g.
"foo/bar/baz") are therefore supplemented with equivalents that
take a list (pdf_dict_getl(... , PDF_NAME_foo, PDF_NAME_bar,
PDF_NAME_baz, NULL)).

The actual implementation of this relies on the fact that small
pointer values are never valid values. For a given pdf_obj *p,
if NULL < (intptr_t)p < PDF_NAME__LIMIT then p is a literal
entry in the name table.

This enables us to do fast pointer compares and to skip expensive
strcmps.

Also, bring "null", "true" and "false" into the same style as PDF names.

Rather than using full pdf_obj structures for null/true/false, use
special pointer values just above the PDF_NAME_ table. This saves
memory and makes comparisons easier.

1 files changed, 51 insertions, 52 deletions

diff --git a/source/pdf/pdf-appearance.c b/source/pdf/pdf-appearance.c
index 52dfba0b..ce533cf4 100644
--- a/source/pdf/pdf-appearance.c
+++ b/source/pdf/pdf-appearance.c
@@ -164,7 +164,7 @@ static void get_font_info(fz_context *ctx, pdf_document *doc, pdf_obj *dr, char
 	if (font_rec->da_rec.font_name == NULL)
 		fz_throw(ctx, FZ_ERROR_GENERIC, "No font name in default appearance");
 
-	font_rec->font = font = pdf_load_font(ctx, doc, dr, pdf_dict_gets(ctx, pdf_dict_gets(ctx, dr, "Font"), font_rec->da_rec.font_name), 0);
+	font_rec->font = font = pdf_load_font(ctx, doc, dr, pdf_dict_gets(ctx, pdf_dict_get(ctx, dr, PDF_NAME_Font), font_rec->da_rec.font_name), 0);
 	font_rec->lineheight = 1.0;
 	if (font && font->ascent != 0.0f && font->descent != 0.0f)
 		font_rec->lineheight = (font->ascent - font->descent) / 1000.0;
@@ -179,13 +179,13 @@ static void font_info_fin(fz_context *ctx, font_info *font_rec)
 
 static void get_text_widget_info(fz_context *ctx, pdf_document *doc, pdf_obj *widget, text_widget_info *info)
 {
-	char *da = pdf_to_str_buf(ctx, pdf_get_inheritable(ctx, doc, widget, "DA"));
+	char *da = pdf_to_str_buf(ctx, pdf_get_inheritable(ctx, doc, widget, PDF_NAME_DA));
 	int ff = pdf_get_field_flags(ctx, doc, widget);
-	pdf_obj *ml = pdf_get_inheritable(ctx, doc, widget, "MaxLen");
+	pdf_obj *ml = pdf_get_inheritable(ctx, doc, widget, PDF_NAME_MaxLen);
 
-	info->dr = pdf_get_inheritable(ctx, doc, widget, "DR");
-	info->col = pdf_dict_getp(ctx, widget, "MK/BG");
-	info->q = pdf_to_int(ctx, pdf_get_inheritable(ctx, doc, widget, "Q"));
+	info->dr = pdf_get_inheritable(ctx, doc, widget, PDF_NAME_DR);
+	info->col = pdf_dict_getl(ctx, widget, PDF_NAME_MK, PDF_NAME_BG, NULL);
+	info->q = pdf_to_int(ctx, pdf_get_inheritable(ctx, doc, widget, PDF_NAME_Q));
 	info->multiline = (ff & Ff_Multiline) != 0;
 	info->comb = (ff & (Ff_Multiline|Ff_Password|Ff_FileSelect|Ff_Comb)) == Ff_Comb;
 
@@ -784,7 +784,7 @@ static int get_matrix(fz_context *ctx, pdf_document *doc, pdf_xobject *form, int
 		if (found)
 		{
 			fz_rect bbox;
-			pdf_to_rect(ctx, pdf_dict_gets(ctx, form->contents, "BBox"), &bbox);
+			pdf_to_rect(ctx, pdf_dict_get(ctx, form->contents, PDF_NAME_BBox), &bbox);
 
 			switch (q)
 			{
@@ -928,7 +928,6 @@ static pdf_xobject *load_or_create_form(fz_context *ctx, pdf_document *doc, pdf_
 	int rot;
 	pdf_obj *formobj = NULL;
 	pdf_xobject *form = NULL;
-	char *dn = "N";
 	fz_buffer *fzbuf = NULL;
 	int create_form = 0;
 
@@ -937,25 +936,25 @@ static pdf_xobject *load_or_create_form(fz_context *ctx, pdf_document *doc, pdf_
 	fz_var(fzbuf);
 	fz_try(ctx)
 	{
-		rot = pdf_to_int(ctx, pdf_dict_getp(ctx, obj, "MK/R"));
-		pdf_to_rect(ctx, pdf_dict_gets(ctx, obj, "Rect"), rect);
+		rot = pdf_to_int(ctx, pdf_dict_getl(ctx, obj, PDF_NAME_MK, PDF_NAME_R, NULL));
+		pdf_to_rect(ctx, pdf_dict_get(ctx, obj, PDF_NAME_Rect), rect);
 		rect->x1 -= rect->x0;
 		rect->y1 -= rect->y0;
 		rect->x0 = rect->y0 = 0;
 		account_for_rot(rect, &mat, rot);
 
-		ap = pdf_dict_gets(ctx, obj, "AP");
+		ap = pdf_dict_get(ctx, obj, PDF_NAME_AP);
 		if (ap == NULL)
 		{
 			ap = pdf_new_dict(ctx, doc, 1);
-			pdf_dict_puts_drop(ctx, obj, "AP", ap);
+			pdf_dict_put_drop(ctx, obj, PDF_NAME_AP, ap);
 		}
 
-		formobj = pdf_dict_gets(ctx, ap, dn);
+		formobj = pdf_dict_get(ctx, ap, PDF_NAME_N);
 		if (formobj == NULL)
 		{
 			formobj = pdf_new_xobject(ctx, doc, rect, &mat);
-			pdf_dict_puts_drop(ctx, ap, dn, formobj);
+			pdf_dict_put_drop(ctx, ap, PDF_NAME_N, formobj);
 			create_form = 1;
 		}
 
@@ -966,7 +965,7 @@ static pdf_xobject *load_or_create_form(fz_context *ctx, pdf_document *doc, pdf_
 			pdf_update_xobject_contents(ctx, doc, form, fzbuf);
 		}
 
-		copy_resources(ctx, form->resources, pdf_get_inheritable(ctx, doc, obj, "DR"));
+		copy_resources(ctx, form->resources, pdf_get_inheritable(ctx, doc, obj, PDF_NAME_DR));
 	}
 	fz_always(ctx)
 	{
@@ -1070,15 +1069,15 @@ static void update_marked_content(fz_context *ctx, pdf_document *doc, pdf_xobjec
 
 static int get_border_style(fz_context *ctx, pdf_obj *obj)
 {
-	char *sname = pdf_to_name(ctx, pdf_dict_getp(ctx, obj, "BS/S"));
+	pdf_obj *sname = pdf_dict_getl(ctx, obj, PDF_NAME_BS, PDF_NAME_S, NULL);
 
-	if (!strcmp(sname, "D"))
+	if (pdf_name_eq(ctx, PDF_NAME_D, sname))
 		return BS_Dashed;
-	else if (!strcmp(sname, "B"))
+	else if (pdf_name_eq(ctx, PDF_NAME_B, sname))
 		return BS_Beveled;
-	else if (!strcmp(sname, "I"))
+	else if (pdf_name_eq(ctx, PDF_NAME_I, sname))
 		return BS_Inset;
-	else if (!strcmp(sname, "U"))
+	else if (pdf_name_eq(ctx, PDF_NAME_U, sname))
 		return BS_Underline;
 	else
 		return BS_Solid;
@@ -1086,7 +1085,7 @@ static int get_border_style(fz_context *ctx, pdf_obj *obj)
 
 static float get_border_width(fz_context *ctx, pdf_obj *obj)
 {
-	float w = pdf_to_real(ctx, pdf_dict_getp(ctx, obj, "BS/W"));
+	float w = pdf_to_real(ctx, pdf_dict_getl(ctx, obj, PDF_NAME_BS, PDF_NAME_W, NULL));
 	return w == 0.0 ? 1.0 : w;
 }
 
@@ -1155,7 +1154,7 @@ void pdf_update_combobox_appearance(fz_context *ctx, pdf_document *doc, pdf_obj
 	{
 		get_text_widget_info(ctx, doc, obj, &info);
 
-		val = pdf_get_inheritable(ctx, doc, obj, "V");
+		val = pdf_get_inheritable(ctx, doc, obj, PDF_NAME_V);
 
 		if (pdf_is_array(ctx, val))
 			val = pdf_array_get(ctx, val, 0);
@@ -1204,7 +1203,7 @@ void pdf_update_pushbutton_appearance(fz_context *ctx, pdf_document *doc, pdf_ob
 	{
 		form = load_or_create_form(ctx, doc, obj, &rect);
 		fzbuf = fz_new_buffer(ctx, 0);
-		tobj = pdf_dict_getp(ctx, obj, "MK/BG");
+		tobj = pdf_dict_getl(ctx, obj, PDF_NAME_MK, PDF_NAME_BG, NULL);
 		if (pdf_is_array(ctx, tobj))
 		{
 			fzbuf_print_color(ctx, fzbuf, tobj, 0, 0.0);
@@ -1243,7 +1242,7 @@ void pdf_update_pushbutton_appearance(fz_context *ctx, pdf_document *doc, pdf_ob
 			fz_buffer_printf(ctx, fzbuf, fmt_f);
 		}
 
-		tobj = pdf_dict_getp(ctx, obj, "MK/BC");
+		tobj = pdf_dict_getl(ctx, obj, PDF_NAME_MK, PDF_NAME_BC, NULL);
 		if (tobj)
 		{
 			fzbuf_print_color(ctx, fzbuf, tobj, 1, 0.0);
@@ -1254,13 +1253,13 @@ void pdf_update_pushbutton_appearance(fz_context *ctx, pdf_document *doc, pdf_ob
 			fz_buffer_printf(ctx, fzbuf, fmt_s);
 		}
 
-		tobj = pdf_dict_getp(ctx, obj, "MK/CA");
+		tobj = pdf_dict_getl(ctx, obj, PDF_NAME_MK, PDF_NAME_CA, NULL);
 		if (tobj)
 		{
 			fz_rect clip = rect;
 			fz_rect bounds;
 			fz_matrix mat;
-			char *da = pdf_to_str_buf(ctx, pdf_get_inheritable(ctx, doc, obj, "DA"));
+			char *da = pdf_to_str_buf(ctx, pdf_get_inheritable(ctx, doc, obj, PDF_NAME_DA));
 			char *text = pdf_to_str_buf(ctx, tobj);
 
 			clip.x0 += btotal;
@@ -1330,7 +1329,7 @@ void pdf_update_text_markup_appearance(fz_context *ctx, pdf_document *doc, pdf_a
 
 static void update_rect(fz_context *ctx, pdf_annot *annot)
 {
-	pdf_to_rect(ctx, pdf_dict_gets(ctx, annot->obj, "Rect"), &annot->rect);
+	pdf_to_rect(ctx, pdf_dict_get(ctx, annot->obj, PDF_NAME_Rect), &annot->rect);
 	annot->pagerect = annot->rect;
 	fz_transform_rect(&annot->pagerect, &annot->page->ctm);
 }
@@ -1354,27 +1353,27 @@ void pdf_set_annot_appearance(fz_context *ctx, pdf_document *doc, pdf_annot *ann
 
 		fz_transform_rect(&trect, &ctm);
 
-		pdf_dict_puts_drop(ctx, obj, "Rect", pdf_new_rect(ctx, doc, &trect));
+		pdf_dict_put_drop(ctx, obj, PDF_NAME_Rect, pdf_new_rect(ctx, doc, &trect));
 
 		/* See if there is a current normal appearance */
-		ap_obj = pdf_dict_getp(ctx, obj, "AP/N");
+		ap_obj = pdf_dict_getl(ctx, obj, PDF_NAME_AP, PDF_NAME_N, NULL);
 		if (!pdf_is_stream(ctx, doc, pdf_to_num(ctx, ap_obj), pdf_to_gen(ctx, ap_obj)))
 			ap_obj = NULL;
 
 		if (ap_obj == NULL)
 		{
 			ap_obj = pdf_new_xobject(ctx, doc, &trect, &mat);
-			pdf_dict_putp_drop(ctx, obj, "AP/N", ap_obj);
+			pdf_dict_putl_drop(ctx, obj, ap_obj, PDF_NAME_AP, PDF_NAME_N, NULL);
 		}
 		else
 		{
 			pdf_xref_ensure_incremental_object(ctx, doc, pdf_to_num(ctx, ap_obj));
 			/* Update bounding box and matrix in reused xobject obj */
-			pdf_dict_puts_drop(ctx, ap_obj, "BBox", pdf_new_rect(ctx, doc, &trect));
-			pdf_dict_puts_drop(ctx, ap_obj, "Matrix", pdf_new_matrix(ctx, doc, &mat));
+			pdf_dict_put_drop(ctx, ap_obj, PDF_NAME_BBox, pdf_new_rect(ctx, doc, &trect));
+			pdf_dict_put_drop(ctx, ap_obj, PDF_NAME_Matrix, pdf_new_matrix(ctx, doc, &mat));
 		}
 
-		dev = pdf_new_pdf_device(ctx, doc, ap_obj, pdf_dict_gets(ctx, ap_obj, "Resources"), &mat, NULL);
+		dev = pdf_new_pdf_device(ctx, doc, ap_obj, pdf_dict_get(ctx, ap_obj, PDF_NAME_Resources), &mat, NULL);
 		fz_run_display_list(ctx, disp_list, dev, &ctm, &fz_infinite_rect, NULL);
 		fz_drop_device(ctx, dev);
 
@@ -1403,7 +1402,7 @@ void pdf_set_annot_appearance(fz_context *ctx, pdf_document *doc, pdf_annot *ann
 static fz_point *
 quadpoints(fz_context *ctx, pdf_document *doc, pdf_obj *annot, int *nout)
 {
-	pdf_obj *quad = pdf_dict_gets(ctx, annot, "QuadPoints");
+	pdf_obj *quad = pdf_dict_get(ctx, annot, PDF_NAME_QuadPoints);
 	fz_point *qp = NULL;
 	int i, n;
 
@@ -1568,7 +1567,7 @@ void pdf_update_ink_appearance(fz_context *ctx, pdf_document *doc, pdf_annot *an
 		int n, m, i, j;
 		int empty = 1;
 
-		cs = pdf_to_color(ctx, doc, pdf_dict_gets(ctx, annot->obj, "C"), color);
+		cs = pdf_to_color(ctx, doc, pdf_dict_get(ctx, annot->obj, PDF_NAME_C), color);
 		if (!cs)
 		{
 			cs = fz_device_rgb(ctx);
@@ -1577,11 +1576,11 @@ void pdf_update_ink_appearance(fz_context *ctx, pdf_document *doc, pdf_annot *an
 			color[2] = 0.0f;
 		}
 
-		width = pdf_to_real(ctx, pdf_dict_gets(ctx, pdf_dict_gets(ctx, annot->obj, "BS"), "W"));
+		width = pdf_to_real(ctx, pdf_dict_get(ctx, pdf_dict_get(ctx, annot->obj, PDF_NAME_BS), PDF_NAME_W));
 		if (width == 0.0f)
 			width = 1.0f;
 
-		list = pdf_dict_gets(ctx, annot->obj, "InkList");
+		list = pdf_dict_get(ctx, annot->obj, PDF_NAME_InkList);
 
 		n = pdf_array_len(ctx, list);
 
@@ -1857,7 +1856,7 @@ void pdf_update_text_annot_appearance(fz_context *ctx, pdf_document *doc, pdf_an
 		fz_rect bounds;
 		fz_matrix tm;
 
-		pdf_to_rect(ctx, pdf_dict_gets(ctx, annot->obj, "Rect"), &rect);
+		pdf_to_rect(ctx, pdf_dict_get(ctx, annot->obj, PDF_NAME_Rect), &rect);
 		dlist = fz_new_display_list(ctx);
 		dev = fz_new_list_device(ctx, dlist);
 		stroke = fz_new_stroke_state(ctx);
@@ -1907,7 +1906,7 @@ void pdf_update_free_text_annot_appearance(fz_context *ctx, pdf_document *doc, p
 {
 	const fz_matrix *page_ctm = &annot->page->ctm;
 	pdf_obj *obj = annot->obj;
-	pdf_obj *dr = pdf_dict_getp(ctx, annot->page->me, "Resources");
+	pdf_obj *dr = pdf_dict_get(ctx, annot->page->me, PDF_NAME_Resources);
 	fz_display_list *dlist = NULL;
 	fz_device *dev = NULL;
 	font_info font_rec;
@@ -1926,8 +1925,8 @@ void pdf_update_free_text_annot_appearance(fz_context *ctx, pdf_document *doc, p
 	fz_var(cs);
 	fz_try(ctx)
 	{
-		char *contents = pdf_to_str_buf(ctx, pdf_dict_gets(ctx, obj, "Contents"));
-		char *da = pdf_to_str_buf(ctx, pdf_dict_gets(ctx, obj, "DA"));
+		char *contents = pdf_to_str_buf(ctx, pdf_dict_get(ctx, obj, PDF_NAME_Contents));
+		char *da = pdf_to_str_buf(ctx, pdf_dict_get(ctx, obj, PDF_NAME_DA));
 		fz_rect rect = annot->rect;
 		fz_point pos;
 
@@ -2029,14 +2028,14 @@ static void draw_logo(fz_context *ctx, fz_path *path)
 
 static void insert_signature_appearance_layers(fz_context *ctx, pdf_document *doc, pdf_annot *annot)
 {
-	pdf_obj *ap = pdf_dict_getp(ctx, annot->obj, "AP/N");
+	pdf_obj *ap = pdf_dict_getl(ctx, annot->obj, PDF_NAME_AP, PDF_NAME_N, NULL);
 	pdf_obj *main_ap = NULL;
 	pdf_obj *frm = NULL;
 	pdf_obj *n0 = NULL;
 	fz_rect bbox;
 	fz_buffer *fzbuf = NULL;
 
-	pdf_to_rect(ctx, pdf_dict_gets(ctx, ap, "BBox"), &bbox);
+	pdf_to_rect(ctx, pdf_dict_get(ctx, ap, PDF_NAME_BBox), &bbox);
 
 	fz_var(main_ap);
 	fz_var(frm);
@@ -2048,15 +2047,15 @@ static void insert_signature_appearance_layers(fz_context *ctx, pdf_document *do
 		frm = pdf_new_xobject(ctx, doc, &bbox, &fz_identity);
 		n0 = pdf_new_xobject(ctx, doc, &bbox, &fz_identity);
 
-		pdf_dict_putp(ctx, main_ap, "Resources/XObject/FRM", frm);
+		pdf_dict_putl(ctx, main_ap, frm, PDF_NAME_Resources, PDF_NAME_XObject, PDF_NAME_FRM, NULL);
 		fzbuf = fz_new_buffer(ctx, 8);
 		fz_buffer_printf(ctx, fzbuf, "/FRM Do");
 		pdf_update_stream(ctx, doc, main_ap, fzbuf, 0);
 		fz_drop_buffer(ctx, fzbuf);
 		fzbuf = NULL;
 
-		pdf_dict_putp(ctx, frm, "Resources/XObject/n0", n0);
-		pdf_dict_putp(ctx, frm, "Resources/XObject/n2", ap);
+		pdf_dict_putl(ctx, frm, n0, PDF_NAME_Resources, PDF_NAME_XObject, PDF_NAME_n0, NULL);
+		pdf_dict_putl(ctx, frm, ap, PDF_NAME_Resources, PDF_NAME_XObject, PDF_NAME_n2, NULL);
 		fzbuf = fz_new_buffer(ctx, 8);
 		fz_buffer_printf(ctx, fzbuf, "q 1 0 0 1 0 0 cm /n0 Do Q q 1 0 0 1 0 0 cm /n2 Do Q");
 		pdf_update_stream(ctx, doc, frm, fzbuf, 0);
@@ -2069,7 +2068,7 @@ static void insert_signature_appearance_layers(fz_context *ctx, pdf_document *do
 		fz_drop_buffer(ctx, fzbuf);
 		fzbuf = NULL;
 
-		pdf_dict_putp(ctx, annot->obj, "AP/N", main_ap);
+		pdf_dict_putl(ctx, annot->obj, main_ap, PDF_NAME_AP, PDF_NAME_N, NULL);
 	}
 	fz_always(ctx)
 	{
@@ -2091,7 +2090,7 @@ void pdf_set_signature_appearance(fz_context *ctx, pdf_document *doc, pdf_annot
 {
 	const fz_matrix *page_ctm = &annot->page->ctm;
 	pdf_obj *obj = annot->obj;
-	pdf_obj *dr = pdf_dict_getp(ctx, pdf_trailer(ctx, doc), "Root/AcroForm/DR");
+	pdf_obj *dr = pdf_dict_getl(ctx, pdf_trailer(ctx, doc), PDF_NAME_Root, PDF_NAME_AcroForm, PDF_NAME_DR, NULL);
 	fz_display_list *dlist = NULL;
 	fz_device *dev = NULL;
 	font_info font_rec;
@@ -2101,7 +2100,7 @@ void pdf_set_signature_appearance(fz_context *ctx, pdf_document *doc, pdf_annot
 	fz_buffer *fzbuf = NULL;
 
 	if (!dr)
-		pdf_dict_putp_drop(ctx, pdf_trailer(ctx, doc), "Root/AcroForm/DR", pdf_new_dict(ctx, doc, 1));
+		pdf_dict_putl_drop(ctx, pdf_trailer(ctx, doc), pdf_new_dict(ctx, doc, 1), PDF_NAME_Root, PDF_NAME_AcroForm, PDF_NAME_DR, NULL);
 
 	memset(&font_rec, 0, sizeof(font_rec));
 
@@ -2113,7 +2112,7 @@ void pdf_set_signature_appearance(fz_context *ctx, pdf_document *doc, pdf_annot
 	fz_var(fzbuf);
 	fz_try(ctx)
 	{
-		char *da = pdf_to_str_buf(ctx, pdf_dict_gets(ctx, obj, "DA"));
+		char *da = pdf_to_str_buf(ctx, pdf_dict_get(ctx, obj, PDF_NAME_DA));
 		fz_rect rect = annot->rect;
 		fz_rect logo_bounds;
 		fz_matrix logo_tm;
@@ -2190,7 +2189,7 @@ void pdf_set_signature_appearance(fz_context *ctx, pdf_document *doc, pdf_annot
 void pdf_update_appearance(fz_context *ctx, pdf_document *doc, pdf_annot *annot)
 {
 	pdf_obj *obj = annot->obj;
-	if (!pdf_dict_gets(ctx, obj, "AP") || pdf_obj_is_dirty(ctx, obj))
+	if (!pdf_dict_get(ctx, obj, PDF_NAME_AP) || pdf_obj_is_dirty(ctx, obj))
 	{
 		fz_annot_type type = pdf_annot_obj_type(ctx, obj);
 		switch (type)
@@ -2201,7 +2200,7 @@ void pdf_update_appearance(fz_context *ctx, pdf_document *doc, pdf_annot *annot)
 			case PDF_WIDGET_TYPE_TEXT:
 				{
 					#if 0
-					pdf_obj *formatting = pdf_dict_getp(ctx, obj, "AA/F");
+					pdf_obj *formatting = pdf_dict_getl(ctx, obj, PDF_NAME_AA, PDF_NAME_F, NULL);
 					if (formatting && doc->js)
 					{
 						/* Apply formatting */