Diff: extlib/BaseJpegDecode/BitPattern.cpp

Revision:

0:d69efd0ee139

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extlib/BaseJpegDecode/BitPattern.cpp	Thu Sep 18 15:21:47 2014 +0000
@@ -0,0 +1,104 @@
+#include "BitPattern.h"
+
+BitPattern::BitPattern()
+{
+    clear();
+}
+
+BitPattern::BitPattern(uint32_t value, int size)
+{
+    clear();
+    put(value, size);
+}
+
+BitPattern::BitPattern(const char* s)
+{
+    clear();
+    operator+=(s);
+}
+
+void BitPattern::clear()
+{
+    m_size = 0;
+    m_pat = 0;
+}
+
+void BitPattern::operator=(const char* s)
+{
+    clear();
+    operator+=(s);
+}
+
+void BitPattern::operator+=(uint8_t c)
+{
+    put(c);
+}
+
+void BitPattern::operator+=(const char* s)
+{
+    for(int i = 0; i < 32 && s[i]; i++) {
+        char c = s[i];
+        put(c-'0', 1);
+    }
+}
+
+int BitPattern::operator [](int index)
+{
+    uint32_t mask = 0x80000000;
+    for(int i = 0; i < index; i++) {
+        mask>>=1;
+    }
+    if (m_pat & mask) {
+        return 1;
+    }
+    return 0;
+}
+
+void BitPattern::put(uint32_t value, int size)
+{
+    m_pat <<= size;
+    m_pat |= value;
+    m_size += size;
+}
+
+uint32_t BitPattern::peek(int size)
+{
+    return m_pat >> (m_size - size);
+}
+
+uint32_t BitPattern::get(int size)
+{
+    uint32_t r = peek(size);
+    m_size -= size;
+    m_pat &= (1<<m_size)-1;
+    return r;
+}
+
+int BitPattern::size()
+{
+    return m_size;
+}
+
+bool BitPattern::match(BitPattern& b)
+{
+    if (b.m_size > m_size) {
+        return false;
+    }
+    return peek(b.size()) == b.peek(b.size());
+}
+
+bool BitPattern::match(const char* s)
+{
+    BitPattern a = s;
+    return match(a);
+}
+
+bool BitPattern::operator ==(BitPattern& b)
+{
+    if (b.m_size == m_size) {
+        if (b.m_pat == m_pat) {
+            return true;
+        }
+    }
+    return false;
+}