anchor.diff:  ExcerptTailer reader = chronicle.createTailer();
   ----
   
  -The `NativeExcerptAppender.startExcerpt` method performs checks and calculates the `startAddr` and `limitAddr(startAddr+100)` for this excerpt.
  -
  -[source,java]
  -----
  -appender.startExcerpt(100);
  -----
  -
  -The `writeObject` method copies the contents of the object into the excerpt:
  -
  -[source,java]
  -----
  -appender.writeObject("TestMessage");
  -----
  -
  -The `finish` method object offset is written to index cache. This method acts like a commit, without writing this offset to cache you put data to the data cache, but not persist it.
  -
  -[source,java]
  -----
  -appender.finish();
  -----
  -
  -In order to read data from the data cache, you first need to get the physical start address of the data from index cache. The `Reader.index(0)` method does the calculation for you. You read the data and finish the reading operation:
  -
  -[source,java]
  -----
  -reader.index(0); // optional as it is at the start already
  -Object ret = reader.readObject();
  -reader.finish();
  -----
  +The `write` and `read` an object 
  +
  +[source,java]
  +----
  +// todo
  +----
  +
   
   == Tiered Indexing
   Chronicle Queue uses tiered multi-level indexing to provide a fast and efficient method for searching for messages in a large queue.
  
positive.code: 
  == Building Blocks
  
  Chronicle Queue has three main conceptual components:
  
   - Tailer - sequential reads
   - Excerpt - random reads
   - Appender - sequential writes
  
  Chronicle Queue is the main interface for management and can be seen as the collection class of the Chronicle environment.
  
  You will reserve a portion of memory and then put/fetch/update records using the Chronicle interface.
  
  Chronicle Queue allows you to put huge numbers of objects of different sizes onto a single queue. For each data record, Chronicle holds the memory-offset in another index cache for random access. This means that Chronicle knows where the 3rd object resides in memory. This index is a sequential index, where the first object has index 0, the second object has index 1, and so on.
  
  An excerpt is the main data container in a Chronicle queue. Each queue is composed of excerpts. Putting data to a queue means starting a new excerpt, writing data into it, and then finishing the excerpt at the end.
  
  An appender is something like an iterator in Chronicle environment. You add data by appending it to the current queue.
  
  === HashMap v B-Tree
  
  HashMap is more performant with lower garbage collection than a B-Tree.  The advantage of a B-Tree is that it is sorted.  If you don't need this, use a hash map of some kind.
  
  == Getting Started
  In the following example we will:
  
  
negative.code: 
  [source,java]
  ----
  // todo
  ----
  
  Create a Chronicle queue giving `Java_temp_directory/SimpleChronicle` as the base folder.
  
  [source,java]
  ----
  // todo
  ----
  
   
  Create appender and reader:
  
  [source,java]
  