From 9897f7581fcde7d430624045850c054b4ebeede4 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Thu, 16 Jan 2014 18:41:10 +0900
Subject: [PATCH] impl pic_fread with buffering

---
 include/picrin/port.h |  1 +
 src/port.c            | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/include/picrin/port.h b/include/picrin/port.h
index 32550231..dd5b8ae0 100644
--- a/include/picrin/port.h
+++ b/include/picrin/port.h
@@ -47,6 +47,7 @@ struct pic_port *pic_stderr(pic_state *);
 
 int pic_setvbuf(pic_file *, char *, int, size_t);
 int pic_fflush(pic_file *);
+int pic_ffill(pic_file *);
 
 pic_file *pic_funopen(void *cookie, int (*read)(void *, char *, int), int (*write)(void *, const char *, int), fpos_t (*seek)(void *, fpos_t, int), int (*close)(void *));
 
diff --git a/src/port.c b/src/port.c
index c62d9252..b6f4845c 100644
--- a/src/port.c
+++ b/src/port.c
@@ -71,6 +71,12 @@ pic_fflush(pic_file *file)
   return file->vtable.write(file->vtable.cookie, file->s, file->c - file->s);
 }
 
+int
+pic_ffill(pic_file *file)
+{
+  return file->vtable.read(file->vtable.cookie, file->c, file->e - file->c);
+}
+
 pic_file *
 pic_funopen(void *cookie,
             int (*read)(void *, char *, int),
@@ -149,6 +155,34 @@ pic_fclose(pic_file *file)
   return 0;
 }
 
+size_t
+pic_fread(void *ptr, size_t block, size_t nitems, pic_file *file)
+{
+  int size, avail;
+  char *dst = (char *)ptr;
+
+  size = block * nitems;        /* TODO: optimize block read */
+
+  while (1) {
+    avail = file->c - file->s;
+    if (size <= avail) {
+      memcpy(dst, file->s, size);
+      file->c -= size;
+      memmove(file->s, file->c, avail - size);
+      break;
+    }
+    else {
+      memcpy(dst, file->s, avail);
+      file->c -= avail;
+      size -= avail;
+      dst += avail;
+      pic_ffill(file);
+    }
+  }
+
+  return block * nitems;
+}
+
 size_t
 pic_fwrite(const void *ptr, size_t block, size_t nitems, pic_file *file)
 {