Initial Contribution

1 files changed, 231 insertions, 0 deletions

diff --git a/cbuffer.c b/cbuffer.c
new file mode 100644
index 0000000..082b0dd
--- /dev/null
+++ b/cbuffer.c
@@ -0,0 +1,231 @@
+/* Copyright (C) 2007-2008 The Android Open Source Project
+**
+** This software is licensed under the terms of the GNU General Public
+** License version 2, as published by the Free Software Foundation, and
+** may be copied, distributed, and modified under those terms.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+** GNU General Public License for more details.
+*/
+#include "cbuffer.h"
+#include "android_utils.h"
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <stdio.h>
+
+#define  DEBUG  0
+
+#if DEBUG
+#  define  ASSERT(cond,fmt,...)  ({ if (!(cond)) { fprintf(stderr, fmt, __VA_ARGS__); assert(cond); } })
+#else
+#  define  ASSERT(cond,fmt,...)  ((void)0)
+#endif
+
+#if DEBUG
+void
+cbuffer_assert( CBuffer*  cb, const char*  file, long  lineno )
+{
+    const char*  reason = NULL;
+
+    if (cb->rpos < 0 || cb->rpos >= cb->size) {
+        reason = "rpos is out of bounds";
+    }
+    else if (cb->count < 0 || cb->count > cb->size) {
+        reason = "count is incorrect";
+    }
+    if (!reason)
+        return;
+
+    fprintf(stderr, "assert:%s:%ld: assertion failed: %s (pos=%d count=%d size=%d)\n",
+            file, lineno, reason, cb->rpos, cb->count, cb->size);
+    assert(0);
+}
+#  define  CBUFFER_ASSERT(cb)  cbuffer_assert(cb,__FUNCTION__,__LINE__)
+#else
+#  define  CBUFFER_ASSERT(cb)  ((void)0)
+#endif
+
+int
+cbuffer_write_peek( CBuffer*  cb, uint8_t*  *pbase )
+{
+    int  wpos  = cb->rpos + cb->count;
+    int  avail = cb->size - cb->count;
+
+    CBUFFER_ASSERT(cb);
+
+    if (wpos >= cb->size)
+        wpos -= cb->size;
+
+    if (wpos + avail > cb->size)
+        avail = cb->size - wpos;
+
+    *pbase = cb->buff + wpos;
+    return avail;
+}
+
+void
+cbuffer_write_step( CBuffer*  cb, int  len )
+{
+    CBUFFER_ASSERT(cb);
+
+    cb->count += len;
+    if (cb->count > cb->size)
+        cb->count = cb->size;
+}
+
+
+int
+cbuffer_write( CBuffer*  cb, const void*  from, int  len )
+{
+    int  len2 = len;
+
+    CBUFFER_ASSERT(cb);
+
+    while (len2 > 0) {
+        int  avail = cb->size - cb->count;
+        int  wpos  = cb->rpos + cb->count;
+
+        ASSERT(avail >= 0, "avail is negative: %d", avail);
+
+        if (avail == 0)
+            break;
+
+        if (wpos >= cb->size)
+            wpos -= cb->size;
+
+        ASSERT( wpos >= 0 && wpos < cb->size, "wpos is out-of-bounds: %d (rpos=%d)", wpos, cb->rpos);
+
+        if (wpos + avail > cb->size)
+            avail = cb->size - wpos;
+
+        if (avail > len2)
+            avail = len2;
+
+        memcpy( cb->buff + wpos, (const char*)from, avail );
+
+        from  = (char*)from + avail;
+        len2 -= avail;
+        cb->count += avail;
+    }
+    return len - len2;
+}
+
+int
+cbuffer_read( CBuffer*  cb, void*  to, int  len )
+{
+    int   len2 = len;
+
+    CBUFFER_ASSERT(cb);
+
+    while (len2 > 0) {
+        int  avail = cb->count;
+        int  rpos = cb->rpos;
+
+        ASSERT(avail >= 0, "avail is negative: %d", avail);
+
+        if (avail == 0)
+            break;
+
+        ASSERT((rpos >= 0 && rpos < cb->size), "rpos is out-of-bounds: %d", rpos);
+
+        if (rpos+avail > cb->size)
+            avail = cb->size - rpos;
+
+        if (avail > len2)
+            avail = len2;
+
+        memcpy( (char*)to, (const char*)cb->buff + rpos, avail );
+        to    = (char*)to + avail;
+        len2 -= avail;
+        cb->count -= avail;
+        cb->rpos  += avail;
+        if (cb->rpos >= cb->size)
+            cb->rpos -= cb->size;
+    }
+    return len - len2;
+}
+
+int
+cbuffer_read_peek( CBuffer*  cb, uint8_t*  *pbase )
+{
+    int   rpos  = cb->rpos;
+    int   avail = cb->count;
+
+    CBUFFER_ASSERT(cb);
+
+    if (rpos + avail > cb->size)
+        avail = cb->size - rpos;
+
+    *pbase = cb->buff + rpos;
+    return avail;
+}
+
+
+void
+cbuffer_read_step( CBuffer*  cb, int  len )
+{
+    CBUFFER_ASSERT(cb);
+
+    if (len > cb->count)
+        len = cb->count;
+
+    cb->rpos  += len;
+    if (cb->rpos >= cb->size)
+        cb->rpos -= cb->size;
+
+    cb->count -= len;
+}
+
+const char*
+cbuffer_quote( CBuffer*  cb )
+{
+    STRALLOC_DEFINE(s);
+    char* q;
+
+    stralloc_format( s, "cbuffer %p (pos=%d count=%d size=%d)",
+                     cb, cb->rpos, cb->count, cb->size );
+
+    q = tempstr_from_stralloc( s );
+    stralloc_reset(s);
+
+    return q;
+}
+
+const char*
+cbuffer_quote_data( CBuffer*  cb )
+{
+    STRALLOC_DEFINE(s);
+    int   len  = cb->count;
+    int   rpos = cb->rpos;
+    char* result;
+
+    while (len > 0) {
+        int  avail = len;
+
+        if (rpos >= cb->size)
+            rpos -= cb->size;
+
+        if (rpos + avail > cb->size)
+            avail = cb->size - rpos;
+
+        stralloc_add_quote_bytes( s, cb->buff + rpos, avail );
+        rpos += avail;
+        len  -= avail;
+    }
+
+    result = tempstr_from_stralloc(s);
+    stralloc_reset(s);
+
+    return result;
+}
+
+void
+cbuffer_print( CBuffer*  cb )
+{
+    /* print the content of a cbuffer */
+    printf( "%s: %s", cbuffer_quote(cb), cbuffer_quote_data(cb) );
+}
+