eliminate support for multiple lws threads as part of fixing valgrind errors

Signed-off-by: Dave Horton <daveh@beachdognet.com>

mod_google_transcribe/simple_buffer.h

@@ -0,0 +1,51 @@
+/**
+ * (very) simple and limited circular buffer, 
+ * supporting only the use case of doing all of the adds
+ * and then subsquently retrieves.
+ * 
+ */
+class SimpleBuffer {
+  public:
+    SimpleBuffer(uint32_t chunkSize, uint32_t numChunks) : numItems(0),
+    m_numChunks(numChunks), m_chunkSize(chunkSize) {
+      m_pData = new char[chunkSize * numChunks];
+      m_pNextWrite = m_pData;
+    }
+    ~SimpleBuffer() {
+      delete [] m_pData;
+    }
+
+    void add(void *data, uint32_t datalen) {
+      if (datalen % m_chunkSize != 0) return;
+      int numChunks = datalen / m_chunkSize;
+      for (int i = 0; i < numChunks; i++) {
+        memcpy(m_pNextWrite, data, m_chunkSize);
+        data = static_cast<char*>(data) + m_chunkSize;
+        if (numItems < m_numChunks) numItems++;
+
+        uint32_t offset = (m_pNextWrite - m_pData) / m_chunkSize;
+        if (offset >= m_numChunks - 1) m_pNextWrite = m_pData;
+        else m_pNextWrite += m_chunkSize;
+      }
+    }
+
+    char* getNextChunk() {
+      if (numItems--) {
+        char *p = m_pNextWrite;
+        uint32_t offset = (m_pNextWrite - m_pData) / m_chunkSize;
+        if (offset >= m_numChunks - 1) m_pNextWrite = m_pData;
+        else m_pNextWrite += m_chunkSize;
+        return p;
+      }
+      return nullptr;
+    }
+
+    uint32_t getNumItems() { return numItems;}
+
+  private:
+    char *m_pData;
+    uint32_t numItems;
+    uint32_t m_chunkSize;
+    uint32_t m_numChunks;
+    char* m_pNextWrite;
+};