Adding seekable buffers. Probably would need a few more tests in the Handles unit test.

1 files changed, 76 insertions, 0 deletions

diff --git a/src/Buffer.cc b/src/Buffer.cc
new file mode 100644
index 0000000..d6ff9bb
--- /dev/null
+++ b/src/Buffer.cc
@@ -0,0 +1,76 @@
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include "Buffer.h"
+#include "Task.h"
+#include "Printer.h"
+
+static const int s_blockSize = 16 * 1024;
+
+void Balau::Buffer::close() throw (GeneralException) {
+    reset();
+}
+
+ssize_t Balau::Buffer::read(void * buf, size_t count) throw (GeneralException) {
+    off_t cursor = rtell();
+    if (cursor >= m_bufSize)
+        return 0;
+    off_t avail = m_bufSize - cursor;
+
+    if (count > avail)
+        count = avail;
+
+    memcpy(buf, m_buffer + cursor, count);
+
+    rseek(cursor + count);
+
+    return count;
+}
+
+ssize_t Balau::Buffer::write(const void * buf, size_t count) throw (GeneralException) {
+    off_t cursor = wtell();
+    off_t end = cursor + count;
+    off_t endBlock = (end / s_blockSize) + ((end % s_blockSize) ? 1 : 0);
+    off_t oldEndBlock = m_numBlocks;
+
+    if (endBlock > oldEndBlock) {
+        m_buffer = (uint8_t *) realloc(m_buffer, endBlock * s_blockSize);
+        memset(m_buffer + oldEndBlock * s_blockSize, 0, (endBlock - oldEndBlock) * s_blockSize);
+    }
+
+    memcpy(m_buffer + cursor, buf, count);
+
+    wseek(cursor + count);
+
+    return count;
+}
+
+void Balau::Buffer::reset() {
+    m_buffer = (uint8_t *) realloc(m_buffer, 0);
+    m_bufSize = 0;
+    m_numBlocks = 0;
+    wseek(0);
+    rseek(0);
+}
+
+bool Balau::Buffer::isClosed() {
+    return false;
+}
+
+const char * Balau::Buffer::getName() {
+    return "Buffer";
+}
+
+off_t Balau::Buffer::getSize() {
+    return m_bufSize;
+}
+
+bool Balau::Buffer::canRead() {
+    return true;
+}
+
+bool Balau::Buffer::canWrite() {
+    return true;
+}