Rewrite hashing to use FT_Stream directly

This is more robust but introduces a small change in behavior:
For .pcf.gz fonts, the new code calculates the hash of the uncompressed
font data whereas the original code was calculating the hash of the
compressed data.

No big deal IMO.

src/fcfreetype.c

@@ -1104,9 +1104,6 @@ FcFreeTypeQueryFace (const FT_Face  face,
     char	    psname[256];
     const char	    *tmp;
 
-    FcChar8	    *hashstr = NULL;
-    FT_Error	    err;
-    FT_ULong	    len = 0, alen;
     FcRange	    *r = NULL;
     double	    lower_size = 0.0L, upper_size = DBL_MAX;
 
@@ -1699,46 +1696,55 @@ FcFreeTypeQueryFace (const FT_Face  face,
     if (!FcPatternAddBool (pat, FC_DECORATIVE, decorative))
 	goto bail1;
 
-    err = FT_Load_Sfnt_Table (face, 0, 0, NULL, &len);
-    if (err == FT_Err_Ok)
-    {
-	char *fontdata;
 
-	alen = (len + 63) & ~63;
-	fontdata = malloc (alen);
-	if (!fontdata)
-	    goto bail3;
-	err = FT_Load_Sfnt_Table (face, 0, 0, (FT_Byte *)fontdata, &len);
-	if (err != FT_Err_Ok)
+    /*
+     * Compute hash digest for the font
+     */
+    {
+	FcChar8	    *hashstr = NULL;
+	FcHashDigest digest;
+
+	FcHashInitDigest (digest);
+
+	if (face->stream->read == NULL)
 	{
-	    free (fontdata);
-	    goto bail3;
+	    const char *data = (const char *) face->stream->base;
+	    size_t total_len = face->stream->size;
+	    size_t len = total_len;
+
+	    while (len >= 64)
+	    {
+		FcHashDigestAddBlock (digest, data);
+		data += 64;
+		len -= 64;
+	    }
+	    FcHashDigestFinish (digest, data, total_len);
+	} else {
+	    char data[64];
+	    size_t total_len = 0;
+	    size_t len = 0;
+
+	    while ((len = face->stream->read (face->stream, total_len, (unsigned char *) data, sizeof(data))) == 64)
+	    {
+		FcHashDigestAddBlock (digest, data);
+		total_len += 64;
+	    }
+	    total_len += len;
+	    FcHashDigestFinish (digest, data, total_len);
 	}
-	memset (&fontdata[len], 0, alen - len);
-	hashstr = FcHashGetDigestFromMemory (fontdata, len);
-	free (fontdata);
-    }
-    else if (err == FT_Err_Invalid_Face_Handle)
-    {
-	/* font may not support SFNT. falling back to
-	 * read the font data from file directly
-	 */
-	hashstr = FcHashGetDigestFromFile (file);
-    }
-    else
-    {
-	goto bail3;
-    }
-    if (hashstr)
-    {
-	if (!FcPatternAddString (pat, FC_HASH, hashstr))
+
+	hashstr = FcHashToString (digest);
+	if (hashstr)
 	{
+	    if (!FcPatternAddString (pat, FC_HASH, hashstr))
+	    {
+		free (hashstr);
+		goto bail1;
+	    }
 	    free (hashstr);
-	    goto bail1;
 	}
-	free (hashstr);
     }
-bail3:
+
 
     /*
      * Compute the unicode coverage for the font

src/fchash.c

@@ -43,9 +43,8 @@
 #define ss1(x)		(ROTR32(x, 17) ^ ROTR32(x, 19) ^ SHR(x, 10))
 
 
-typedef FcChar32 FcHashDigest[8];
 
-static void
+void
 FcHashInitDigest (FcHashDigest digest)
 {
     static const FcHashDigest init = {
@@ -56,7 +55,7 @@ FcHashInitDigest (FcHashDigest digest)
     memcpy (digest, init, sizeof (FcHashDigest));
 }
 
-static void
+void
 FcHashDigestAddBlock (FcHashDigest digest,
 		      const char   block[64])
 {
@@ -129,7 +128,7 @@ FcHashDigestAddBlock (FcHashDigest digest,
 #undef H
 }
 
-static void
+void
 FcHashDigestFinish (FcHashDigest  digest,
 		    const char   *residual, /* < 64 bytes */
 		    size_t        total_len)
@@ -164,7 +163,7 @@ FcHashDigestFinish (FcHashDigest  digest,
     FcHashDigestAddBlock (digest, ibuf);
 }
 
-static FcChar8 *
+FcChar8 *
 FcHashToString (const FcHashDigest digest)
 {
     FcChar8 *ret = NULL;
@@ -188,69 +187,3 @@ FcHashToString (const FcHashDigest digest)
 
     return ret;
 }
-
-FcChar8 *
-FcHashGetDigestFromFile (const FcChar8 *filename)
-{
-    FcHashDigest digest;
-    FILE *fp;
-    char ibuf[64];
-    size_t len;
-    struct stat st;
-
-    fp = fopen ((const char *)filename, "rb");
-    if (!fp)
-	return NULL;
-
-    FcHashInitDigest (digest);
-
-    if (FcStat (filename, &st))
-	goto bail0;
-
-    while (!feof (fp))
-    {
-	if ((len = fread (ibuf, sizeof (char), 64, fp)) < 64)
-	{
-	    FcHashDigestFinish (digest, ibuf, st.st_size);
-	    break;
-	}
-	else
-	{
-	    FcHashDigestAddBlock (digest, ibuf);
-	}
-    }
-    fclose (fp);
-
-    return FcHashToString (digest);
-
-bail0:
-    fclose (fp);
-
-    return NULL;
-}
-
-FcChar8 *
-FcHashGetDigestFromMemory (const char *fontdata,
-			   size_t      length)
-{
-    FcHashDigest digest;
-    size_t i = 0;
-
-    FcHashInitDigest (digest);
-
-    while (i <= length)
-    {
-	if ((length - i) < 64)
-	{
-	    FcHashDigestFinish (digest, fontdata+i, length);
-	    break;
-	}
-	else
-	{
-	    FcHashDigestAddBlock (digest, &fontdata[i]);
-	}
-	i += 64;
-    }
-
-    return FcHashToString (digest);
-}

src/fcint.h

@@ -867,12 +867,23 @@ FcPrivate FcFontSet *
 FcFontSetDeserialize (const FcFontSet *set);
 
 /* fchash.c */
-FcPrivate FcChar8 *
-FcHashGetDigestFromFile (const FcChar8 *filename);
+
+typedef FcChar32 FcHashDigest[8];
+
+FcPrivate void
+FcHashInitDigest (FcHashDigest digest);
+
+FcPrivate void
+FcHashDigestAddBlock (FcHashDigest digest,
+		      const char   block[64]);
+
+FcPrivate void
+FcHashDigestFinish (FcHashDigest  digest,
+		    const char   *residual, /* < 64 bytes */
+		    size_t        total_len);
 
 FcPrivate FcChar8 *
-FcHashGetDigestFromMemory (const char *fontdata,
-			   size_t      length);
+FcHashToString (const FcHashDigest digest);
 
 /* fcinit.c */
 FcPrivate FcConfig *