From a72bbb26973d73ce98c1dde62f3a114e2bb6589c Mon Sep 17 00:00:00 2001
From: Pierre Habouzit <madcoder@debian.org>
Date: Fri, 11 Jan 2008 23:01:32 +0100
Subject: [PATCH] More buffer functions.

---
 lib-lib/buffer.c | 74 +++++++++++++++++++++++-------------------------
 lib-lib/buffer.h | 11 ++++++-
 lib-lib/mem.h    | 14 +++++++++
 3 files changed, 60 insertions(+), 39 deletions(-)

diff --git a/lib-lib/buffer.c b/lib-lib/buffer.c
index 25f930d..f27dc51 100644
--- a/lib-lib/buffer.c
+++ b/lib-lib/buffer.c
@@ -28,20 +28,48 @@
 
 #include "lib-lib.h"
 
-#define BUFSIZ_INCREMENT  1024
-
-void buffer_resize(buffer_t *buf, ssize_t newsize)
+void buffer_splice(buffer_t *buf, ssize_t pos, ssize_t len,
+                   const void *data, ssize_t dlen)
 {
-    if (newsize >= buf->size) {
-        /* rounds newsize to the 1024 multiple just after newsize+1 */
-        newsize = (newsize + BUFSIZ_INCREMENT) & ~(BUFSIZ_INCREMENT - 1);
-        p_realloc(&buf->data, newsize);
-    }
+    if (dlen >= len)
+        buffer_extend(buf, dlen - len);
+    memmove(buf->data + pos + dlen,
+            buf->data + pos + len,
+            buf->len - pos - len);
+    memcpy(buf->data + pos, data, dlen);
+    buffer_setlen(buf, buf->len + dlen - len);
 }
 
+ssize_t buffer_addvf(buffer_t *buf, const char *fmt, va_list args)
+{
+    ssize_t len;
+    va_list ap;
 
+    va_copy(ap, args);
+    buffer_ensure(buf, BUFSIZ);
+
+    len = vsnprintf(buf->data + buf->len, buf->size - buf->len, fmt, args);
+    if (len < 0)
+        return len;
+    if (len >= buf->size - buf->len) {
+        buffer_ensure(buf, len);
+        vsnprintf(buf->data + buf->len, buf->size - buf->len, fmt, ap);
+    }
+    buf->len += len;
+    buf->data[buf->len] = '\0';
 
+    return len;
+}
 
+ssize_t buffer_addf(buffer_t *buf, const char *fmt, ...)
+{
+    ssize_t res;
+    va_list args;
+    va_start(args, fmt);
+    res = buffer_addvf(buf, fmt, args);
+    va_end(args);
+    return res;
+}
 /****** LEGACY BUFFERS *******/
 
 /*
@@ -107,33 +135,3 @@ void mutt_buffer_add(BUFFER *buf, const char *s, ssize_t len)
     *buf->dptr = '\0';
 }
 
-ssize_t buffer_addvf(buffer_t *buf, const char *fmt, va_list args)
-{
-    ssize_t len;
-    va_list ap;
-
-    va_copy(ap, args);
-    buffer_ensure(buf, BUFSIZ);
-
-    len = vsnprintf(buf->data + buf->len, buf->size - buf->len, fmt, args);
-    if (len < 0)
-        return len;
-    if (len >= buf->size - buf->len) {
-        buffer_ensure(buf, len);
-        vsnprintf(buf->data + buf->len, buf->size - buf->len, fmt, ap);
-    }
-    buf->len += len;
-    buf->data[buf->len] = '\0';
-
-    return len;
-}
-
-ssize_t buffer_addf(buffer_t *buf, const char *fmt, ...)
-{
-    ssize_t res;
-    va_list args;
-    va_start(args, fmt);
-    res = buffer_addvf(buf, fmt, args);
-    va_end(args);
-    return res;
-}
diff --git a/lib-lib/buffer.h b/lib-lib/buffer.h
index 6d62f2a..41f9ccf 100644
--- a/lib-lib/buffer.h
+++ b/lib-lib/buffer.h
@@ -50,13 +50,20 @@ static inline char *buffer_unwrap(buffer_t **buf) {
 }
 
 
-void buffer_resize(buffer_t *, ssize_t newsize);
+static inline void buffer_resize(buffer_t *buf, ssize_t newsize) {
+    p_allocgrow(&buf->data, newsize + 1, &buf->size);
+}
 static inline void buffer_ensure(buffer_t *buf, ssize_t extra) {
     assert (extra >= 0);
     if (buf->len + extra >= buf->size) {
         buffer_resize(buf, buf->len + extra);
     }
 }
+static inline void buffer_setlen(buffer_t *buf, ssize_t len) {
+    assert (buf->size > len);
+    buf->len = len;
+    buf->data[len] = '\0';
+}
 static inline void buffer_extend(buffer_t *buf, ssize_t extra) {
     buffer_ensure(buf, extra);
     buf->len += extra;
@@ -93,6 +100,8 @@ static inline void buffer_reset(buffer_t *buf) {
     }
 }
 
+void buffer_splice(buffer_t *, ssize_t pos, ssize_t len, const void *, ssize_t);
+
 ssize_t buffer_addvf(buffer_t *buf, const char *fmt, va_list)
     __attribute__((format(printf, 2, 0)));
 
diff --git a/lib-lib/mem.h b/lib-lib/mem.h
index ca9712b..8d904b3 100644
--- a/lib-lib/mem.h
+++ b/lib-lib/mem.h
@@ -29,6 +29,20 @@
 #define p_dupstr(p, len)        xmemdupstr((p), (len))
 #define p_realloc(pp, count)    xrealloc((void*)(pp), sizeof(**(pp)) * (count))
 
+#define p_alloc_nr(x) (((x) + 16) * 3 / 2)
+
+#define p_allocgrow(pp, goalnb, allocnb)                  \
+  do {                                                    \
+      if ((goalnb) > *(allocnb)) {                        \
+          if (p_alloc_nr(*(allocnb)) < (goalnb)) {        \
+              *(allocnb) = (goalnb);                      \
+          } else {                                        \
+              *(allocnb) = p_alloc_nr(*(allocnb));        \
+          }                                               \
+          p_realloc(pp, *(allocnb));                      \
+      }                                                   \
+  } while (0)
+
 #ifdef __GNUC__
 
 #  define p_delete(mem_pp)                          \
-- 
2.20.1