From e3f62ad82e2b88c52c34dcf6b769ba517e7e57f9 Mon Sep 17 00:00:00 2001
From: Pavel Charvat <pavel.charvat@netcentrum.cz>
Date: Wed, 17 May 2006 10:01:20 +0200
Subject: [PATCH] simple bgets with allocation on the stack/mempool/bbuf

---
 lib/fastbuf.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/fastbuf.h |  9 ++++++++
 2 files changed, 72 insertions(+)

diff --git a/lib/fastbuf.c b/lib/fastbuf.c
index f83b4021..9a1cd4a5 100644
--- a/lib/fastbuf.c
+++ b/lib/fastbuf.c
@@ -9,6 +9,7 @@
 
 #include "lib/lib.h"
 #include "lib/fastbuf.h"
+#include "lib/mempool.h"
 
 #include <stdlib.h>
 
@@ -282,6 +283,68 @@ bgets_nodie(struct fastbuf *f, byte *b, uns l)
   return -1;
 }
 
+uns
+bgets_bb(struct fastbuf *f, bb_t *b)
+{
+  for (uns l = 0;; l++)
+    {
+      int k = bgetc(f);
+      byte *p = bb_grow(b, l + 1) + l;
+      if (k == '\n' || k < 0)
+	{
+	  *p = 0;
+	  return l;
+	}
+      *p = k;
+    }
+}
+
+byte *
+bgets_mp(struct mempool *mp, struct fastbuf *f)
+{
+  uns len = 256, l = 0;
+  byte *buf = alloca(len);
+  for (;;)
+    {
+      while (l < len)
+        {
+          int k = bgetc(f);
+          if (k == '\n' || k < 0)
+	    {
+	      byte *result = mp_alloc(mp, l + 1);
+	      memcpy(result, buf, l);
+	      result[l] = 0;
+	      return result;
+	    }
+	  buf[l++] = k;
+        }
+      byte *old_buf = buf;
+      uns old_len = len;
+      len *= 2;
+      buf = alloca(len);
+      memcpy(buf, old_buf, old_len);
+    }
+}
+
+int
+bgets_stk_step(struct fastbuf *f, byte *old_buf, byte *buf, uns len)
+{
+  if (old_buf)
+    {
+      len = len >> 1;
+      memcpy(buf, old_buf, len);
+      buf += len;
+    }
+  while (len--)
+    {
+      int k = bgetc(f);
+      if (k == '\n' || k < 0)
+	return *buf = 0;
+      *buf++ = k;
+    }
+  return 1;
+}
+
 byte *
 bgets0(struct fastbuf *f, byte *b, uns l)
 {
diff --git a/lib/fastbuf.h b/lib/fastbuf.h
index af6787ae..bc7ef7eb 100644
--- a/lib/fastbuf.h
+++ b/lib/fastbuf.h
@@ -16,8 +16,10 @@
 #endif
 
 #include <string.h>
+#include <alloca.h>
 
 #include "lib/unaligned.h"
+#include "lib/bbuf.h"
 
 /*
  *  Generic buffered I/O. You supply hooks to be called for low-level operations
@@ -319,6 +321,13 @@ byte *bgets(struct fastbuf *f, byte *b, uns l);	/* Non-std */
 int bgets_nodie(struct fastbuf *f, byte *b, uns l);
 byte *bgets0(struct fastbuf *f, byte *b, uns l);
 
+struct mempool;
+uns bgets_bb(struct fastbuf *f, bb_t *b);
+byte *bgets_mp(struct mempool *mp, struct fastbuf *f);
+int bgets_stk_step(struct fastbuf *f, byte *old_buf, byte *buf, uns len);
+#define bgets_stk(f) ({ struct fastbuf *_fb = (f); uns _l = 256; byte *_b, *_p = NULL; \
+	while (bgets_stk_step(_fb, _p, _b = alloca(_l), _l)) _p = _b, _l *= 2; _b; })
+
 static inline void
 bputs(struct fastbuf *f, byte *b)
 {
-- 
2.39.2