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@@ -0,0 +1,92 @@ +OBSERVATIONS + +STORAGE + An ltable consists of its size and a "string" table (char**). + An ltable is initialized with a size, that can be 0. The table inside the ltable is NOT initalized. + An ltable is written to disk in the following format: + - 1 byte as a header that stores the 'L' ASCII character. + - 8 bytes (64 bits) that store the size of the table. + - For each "string" in its table, it has: + · 4 bytes (32 bits) that stores the string size (counting the trailing 0). + · However many bytes as size, for storing each of the caracters in the string, including the trailing 0. + -1 byte as an "end" that stores the 'E' ASCII character. + When loading an ltable, if the header doesn't match, it will print "Header is '(header)' not 'L'" to standard error. + Likewise, if the "end" doesn't match, it will print "End is '(end)' not 'E'" to standard error. + Storing an ltable returns 0 upon completion. + When working with "strings", all "strings" are normalized with normalizeStrLimit, lowercasing it, removing trailing spaces and adding a limit of MAXPATH-1 characters plus the trailing 0. + Adding a "string" to an ltable consists of: + - Creating a new table of size size+1. + - Storing all existing "strings" in said table. + - Appending the new "string" at the end of the table. + - Reallocating space in the ltable's table. + - Storing all "strings" in the new table in the ltable's table. + - Increasing the ltable's size by 1. + If the "string" is already on the table, it returns -1. Otherwise, upon it returns 0 upon completion. + Searching for a "string" returns the index [0 ... size-1] of said "string" in the table, or -1 if its not found. + + An htable consists of its size and an unsigned 64 bit integer table. + An htable is initialized with a size, that can be 0. The table inside the htable IS initialized. + An htable is written to disk in the following format: + - 1 byte as a header that stores the 'H' ASCII character. + - 8 bytes (64 bits) that store the size of the table. + - 8 bytes (64 bits) for each element in its table. + - 1 byte as a "end" that stores the 'E' ASCII character. + When loading an htable, if the header doesn't match, it will print "Header is '(header)' not 'H'" to standard error. + Likewise, if the "end" doesn't match, it will print "End is '(end)' not 'E'" to standard error. + Storing an htable returns 0 upon completion. + Adding a 64 bit unsigned integer to an htable consists of: + - Creating a new table of size size+1. + - Storing all existing 64 bit unsigned integers in said table. + - Appending the new 64 bit unsigned integer at the end of the table. + - Reallocating space in the htable's table. + - Storing all 64 bit unsigned integers in the new table in the htable's table. + - Increasing the htable's size by 1. + If the 64 bit unsigned integer is already on the table, it returns -1. Otherwise, upon it returns 0 upon completion. + Searching for a 64 bit unsigned integer returns the index [0 ... size-1] of said 64 bit unsigned integer in the table, or -1 if its not found. + + An mtable consists of its size and a struct relation table. + A struct relation consists of two 64 bit numbers. The first one is the file identifier and the second one the tag identifier. + An mtable is initialized with a size, that can be 0. The table inside the mtable is NOT initialized. + An mtable is written to disk in the following format: + - 1 byte as a header that stores the 'M' ASCII character. + - 8 bytes (64 bits) that store the size of the table. + - For each struct relation in its table, it has: + · 8 bytes (64 bits) that store the file identifier of the relation. + · 8 bytes (64 bits) that store the tag identifier of the relation. + - 1 byte as a "end" that stores the 'E' ASCII character. + When loading an mtable, if the header doesn't match, it will print "Header is '(header)' not 'M'" to standard error. + Likewise, if the "end" doesn't match, it will print "End is '(end)' not 'E'" to standard error. + Storing an mtable returns 0 upon completion. + Adding a relation to an mtable consists of: + - Creating a new table of size size+1. + - Storing all existing relations in said table. + - Appending the new relation at the end of the table. + - Reallocating space in the mtable's table. + - Storing all relations in the new table in the mtable's table. + - Increasing the mtable's size by 1. + If the relation is already on the table, it returns -1. Otherwise, upon it returns 0 upon completion. + Searching for a relation returns the index [0 ... size-1] of said relation in the table, or -1 if its not found. + + +DATABASE + + A database consists of a 32 character (including trailing 0) name, and: + - 2 lookup tables (ltable) for storing the unique file and tag names. + - 2 hash tables (htable) for storing the hashes of the names in the ltables. + - 1 mapping tables (mtable) for storing the mappings of the tags to the files. + The lookup tables serve the purpose of looking up the names of the files and tags when needed. + The hash tables serve the purpose of providing faster search times when searching for a file or tag. + Each respective lookup and hash tables (lfiles and hfiles, ltags and htags) share indexes. + The mapping table serves the purpose of storing the relation between different files and tags as the pairing of their indexes. + A databbase is written to disk in the following format: + - 2 bytes as a header that store the 'DB' ASCII characters. + - 32 bytes that store the name of the database. + - The lfiles ltable. + - The ltags ltable. + - The hfiles htable. + - The htags htable. + - The map mtable. + - 3 bytes as "end" that store the 'END'"' ASCII characters. + When loading a database, if the header doesn't match, it will print "Header is '(header)' not 'DB'" to standard error. + Likewise, if the "end" doesn't match, it will print "End is '(end)' not 'END'" to standard error. + Storing a database returns 0 upon completion. |