Back to looking at raw binary

learn_pytables.py

@@ -4,8 +4,8 @@ import tables
 
 
 class KeyValue(tables.IsDescription):
-    key = tables.StringCol(itemsize=22, dflt=" ", pos=0)
-    value = tables.StringCol(itemsize=22, dflt=" ", pos=0)
+    key = tables.StringCol(itemsize=250, dflt=" ", pos=0)
+    value = tables.VLStringAtom() # StringCol(itemsize=22, dflt=" ", pos=0)
 
 
 def make_notification():
@@ -23,7 +23,9 @@ fileh = tables.open_file("storeage.h5", mode = "w")
 root = fileh.root
 
 notifications = fileh.create_group(root, "notifications")
-notification = fileh.create_table(notifications, "notification", KeyValue)
+notification = fileh.create_table(notifications, "notification", 
+                                  tables.StringCol(itemsize=250, dflt=" ", pos=0))
+vlarray = fileh.createVLArray(notifications, 'vlarray8', tables.VLStringAtom(), "Variable Length String")
 
 row = notification.row
 

shoebox/shoebox.py

@@ -14,24 +14,33 @@
 # limitations under the License.
 
 import datetime
+import struct
 
 """Binary data archiving library.
 
 Data is written in the following format:
 
-[HEADER]
-[PAYLOAD]
-[FOOTER]
+[ENTRY] =
+    <START-OF-BLOCK> byte     # 0x05
+    <BLOCK-TYPE> long         # new versions get new block-types
+    <CRC> ulong
+    <SIZE> long
 
-where:
-    [HEADER] =
-        [START-OF-BLOCK]
-        [BLOCK-TYPE]
-        [SIZE]
+[PAYLOAD] =
+    <START-OF-PAYLOAD> byte     # 0x06
+    <RECORD_COUNT> int
+    [RECORD, RECORD, ...]
 
-    [FOOTER] =
-        [CRC]
-        [END-OF-BLOCK]
+[RECORD] = 
+    <SIZE> long
+    <KEY> varstr (%s)
+    <TYPE> int
+    <UNION>
+        <BOOLEAN>
+        <INT>
+        <FLOAT>
+        <DATETIME>
+        <STRING>
 
 There are ArchiveReaders and ArchiveWriters which are managed
 by RollManager. The RollManager opens and closes Archivers as
@@ -162,6 +171,7 @@ class ArchiveWriter(Archive):
         self._handle = open(filename, "wb+")
 
     def write(self, payload):
+
         pass