Wow, MyriadFs is actually getting workable. You can create files, read, write,

etc.  Next up is creating directories, and other special file types.

1 files changed, 94 insertions, 6 deletions

diff --git a/src/myriadfs.h b/src/myriadfs.h
index 856137c..808444b 100644
--- a/src/myriadfs.h
+++ b/src/myriadfs.h
@@ -19,13 +19,10 @@ namespace Bu
         /**
          * A POSIX compliant, node based filesystem built on top of Myriad.
          *
-         * Think about putting this all in one stream, on block boundaries.
-         *
          * A header is placed into stream 1.
          * Header format:
          *   int32_t iMagicHeader  (A7188B39)
          *   int8_t iVersion (1)
-         *   int32_t iNodeSize
          *   int32_t iNumNodes
          *   NodeLookup[iNumNodes] nNode
          *
@@ -33,10 +30,10 @@ namespace Bu
          *   int32_t iInode
          *   int32_t iPosition
          *
-         * The node headers or inode structures have a base size of 22 bytes.
+         * The node headers or inode structures have a base size of 46 bytes.
          * Everything else in the block is used for the name.  I.e. if you have
          * a blocksize of 512 bytes then you wind up with a max name size of
-         * 512-22=490 characters, or a blocksize of 256 gives you 234 chraacters
+         * 512-46=466 characters, or a blocksize of 256 gives you 210 chraacters
          * as a max.  The node headers are all stored in stream 2.
          * Basic node header format:
          *   int32_t iUser
@@ -50,6 +47,27 @@ namespace Bu
          *   int64_t iCTime
          *   int16_t iNameSize
          *   char[iNameSize] sName
+         *
+         * Some types get special formats for their assosiated data stream, or
+         * other special considerations, here's a list:
+         *
+         * - typeFifo: No stream, iStreamIndex unused (probably)
+         * - typeChrDev: No stream, iStreamIndex is device hi/lo
+         * - typeDir: The stream contains a directory contents listing, described
+         *            below
+         * - typeBlkDev: No stream, iStreamIndex is device hi/lo
+         * - typeRegFile: The stream is the file data
+         * - typeSymLink: The stream is the destination of the symlink
+         * - typeSocket: No steram, iStreamIndex unused (probably)
+         *
+         * Directory streams have this simple listing format.  They contain a list
+         * of all child elements, with no particular order at the moment.  The . and
+         * .. entries are not listed, they are implicit:
+         *   int32_t iNumNodes
+         *   NodeTable[iNumNodes] nChildren
+         *
+         * NodeTable:
+         *   int32_t iInode
          */
         class MyriadFs
         {
@@ -79,11 +97,81 @@ namespace Bu
                         typeSymLink     = 0120000,
                         typeSocket      = 0140000,
                         typeMask        = 0170000
-                }
+                };
+
+                enum
+                {
+                        Read            = 0x01, ///< Open file for reading
+                        Write           = 0x02, ///< Open file for writing
+                        Create          = 0x04, ///< Create file if it doesn't exist
+                        Truncate        = 0x08, ///< Truncate file if it does exist
+                        Append          = 0x10, ///< Always append on every write
+                        NonBlock        = 0x20, ///< Open file in non-blocking mode
+                        Exclusive       = 0x44, ///< Create file, if it exists then fail
+
+                        // Helpful mixes
+                        ReadWrite       = 0x03, ///< Open for reading and writing
+                        WriteNew        = 0x0E  ///< Create a file (or truncate) for writing.
+                                                                /// Same as Write|Create|Truncate
+                };
+                
+                class Stat
+                {
+                public:
+                        int32_t iNode;
+                        int32_t iUser;
+                        int32_t iGroup;
+                        uint16_t uPerms;
+                        int16_t iLinks;
+                        int64_t iATime;
+                        int64_t iMTime;
+                        int64_t iCTime;
+                        int32_t iSize;
+                        Bu::String sName;
+                };
+                typedef Bu::List<Stat> Dir;
+
+                void stat( const Bu::String &sPath, Stat &rBuf );
+                MyriadStream open( const Bu::String &sPath, int iMode );
+//              void create( const Bu::String &sPath, uint16_t iPerms );
+
+
+        private:
+                class RawStat
+                {
+                public:
+                        int32_t iUser;
+                        int32_t iGroup;
+                        uint16_t uPerms;
+                        int16_t iLinks;
+                        int32_t iStreamIndex;
+                        int32_t iParentNode;
+                        int64_t iATime;
+                        int64_t iMTime;
+                        int64_t iCTime;
+                        int16_t iNameSize;
+                };
+                typedef Bu::Hash<int32_t, int32_t> NodeIndex;
+
+        private:
+                int32_t lookupInode( const Bu::String &sPath, int32_t &iParent );
+                int32_t lookupInode( Bu::String::const_iterator iStart,
+                                int32_t iNode, int32_t &iParent );
+                Dir readDir( int32_t iNode );
+                MyriadStream openByInode( int32_t iNode );
+                int32_t create( int32_t iParent, const Bu::String &sName,
+                                uint16_t uPerms );
+                int32_t allocInode( const Bu::String &sName, int32_t iParent,
+                                uint16_t uPerms );
+                void stat( int32_t iNode, Stat &rBuf, MyriadStream &rIs );
+                void writeHeader();
 
         private:
                 Bu::Stream &rStore;
                 Bu::Myriad mStore;
+                NodeIndex hNodeIndex;
+                int32_t iUser;
+                int32_t iGroup;
         };
 };