Re: [ft] Minimizing small file reads
Hi, As Mickey Gabel has proposed, it is possible to load a font face from a memory image that is copied from a font file. Please check FT_Open_Face() API http://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_Open_Face and its argument http://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_Open_Args It is possible to make a FT_Face object from a memory image. If you want a concrete example, please check an implementation of a private internal function open_face_from_buffer() in src/base/ftobjs.c. Regards, mpsuzuki ☂Josh Chia (谢任中) wrote: Hi If you're talking about mmap(), yes my system has mmap, but I'll have to check whether I have it enabled in my freetype build. I notice that freetype is reading little pieces of data, like a long here and there. I also see larger chunks of 4k being read, but ideally, I would like to have everything in memory so that I don't need any calls to read() after some initial read(s). Perhaps, there's a way to prefetch entire font files? If mmap() can be used to avoid small reads, I should probably investigate how to make use of it. Josh On Mon, Nov 17, 2008 at 9:34 PM, suzuki toshiya [EMAIL PROTECTED]wrote: Hi, In the system supporting memmap() and FreeType2 is configured to use it, the number of system call would be much reduced in comparison with the system without memmap. In the target platform which you're working for, memmap() is available? Or, available and configured to use it, but you think still too many read system call is executed? Regards, mpsuzuki ☂Josh Chia (谢任中) wrote (2008/11/18 10:39): Hi, I notice that freetype makes a lot of small reads, resulting in a lot of SYS_read calls. I'm using freetype in an app that runs in a ptrace sandbox, so performance is sensitive to system calls. Is there a simple way to prevent the numerous small reads (via ft_ansi_stream_io), such as configuring freetype to prefetch into a large buffer when reading, and making it assume that font files never change? Will I need to make some configuration changes or do I need to make code changes? Thanks! Josh ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype
Re: [ft] Minimizing small file reads
What about loading the font completely into memory and having FT2 work on the loaded buffer? suzuki toshiya wrote: Hi, In the system supporting memmap() and FreeType2 is configured to use it, the number of system call would be much reduced in comparison with the system without memmap. In the target platform which you're working for, memmap() is available? Or, available and configured to use it, but you think still too many read system call is executed? Regards, mpsuzuki ☂Josh Chia (谢任中) wrote (2008/11/18 10:39): Hi, I notice that freetype makes a lot of small reads, resulting in a lot of SYS_read calls. I'm using freetype in an app that runs in a ptrace sandbox, so performance is sensitive to system calls. Is there a simple way to prevent the numerous small reads (via ft_ansi_stream_io), such as configuring freetype to prefetch into a large buffer when reading, and making it assume that font files never change? Will I need to make some configuration changes or do I need to make code changes? Thanks! Josh ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype
Re: [ft] Minimizing small file reads
Hi, In the system supporting memmap() and FreeType2 is configured to use it, the number of system call would be much reduced in comparison with the system without memmap. In the target platform which you're working for, memmap() is available? Or, available and configured to use it, but you think still too many read system call is executed? Regards, mpsuzuki ☂Josh Chia (谢任中) wrote (2008/11/18 10:39): Hi, I notice that freetype makes a lot of small reads, resulting in a lot of SYS_read calls. I'm using freetype in an app that runs in a ptrace sandbox, so performance is sensitive to system calls. Is there a simple way to prevent the numerous small reads (via ft_ansi_stream_io), such as configuring freetype to prefetch into a large buffer when reading, and making it assume that font files never change? Will I need to make some configuration changes or do I need to make code changes? Thanks! Josh ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype
