Also knows as #~ Stream. This stream begins with a header I call "MetaData Tables Header", here are the members:
Reserved The first dword is always 0.
MajorVersion and MinorVersion Two bytes.
HeapOffsetSizes This field is very important, it's a byte that tells us the size that indexes into the "#String", "#GUID" and "#Blob" streams will have. I paste you the description and the bit mask from the SDK:
"The HeapSizes field is a bitvector that encodes how wide indexes into the various heaps are. If bit 0 is set, indexes into the “#String” heap are 4 bytes wide; if bit 1 is set, indexes into the “#GUID” heap are 4 bytes wide; if bit 2 is set, indexes into the “#Blob” heap are 4 bytes wide. Conversely, if the HeapSize bit for a particular heap is not set, indexes into that heap are 2 bytes wide."
Bitmask Description
0x01 Size of “#String” stream >= 2^16.
0x02 Size of “#GUID” stream >= 2^16
0x04 Size of “#Blob” stream >= 2^16.
Reserved Byte, always 1.
Valid It's a bitmask-qword that tells us which MetaData Tables are present in the assembly. Of course, since this is a qword the maximum number of tables is 64. However, most of the tables aren't defined yet. So, the high bits of this qword are always 0.
Sorted Also a bitmask-qword. It tells us which tables are sorted.
Following there's an array of dwords with the number of rows for each present table. Ok this has to be explained. For every table there can be n rows. Let's say we have three tables: A, B and C. And the Valid mask tells us that the B table is not present, but A and C are. In this case there will be 2 dwords (not three), one for the rows in the A table and one for the C table. The B table rows are skypped since there is no B table in the assembly.
Following the array we find the actual MetaData Tables. The defined tables are:
