This segment describes the two associate structures and the first routine that initialzed parameter table
LITEM STRUCTURE
00 Status dw -1 If never used, NULL otherwise
02 Tstamp dd Timestamp when entry was created
06 Prev dw Pointer to node previous to this one alpha-numerically
08 Next dw " " " next " " " " "
0A Chars dw Length of entry excluding null
0C Offset dd This entries beginning position in TxtPntr
= 10 <16> Bytes
Reserved parts of structure for future expansion and to padd structure to 128 bytes
LPARAM STRUCTURE
00 Status dw Bit 0 = 1 Intialized ready for use
02 Tstamp dd TimeStamp of lists creation
06 Reserved db (10)
10 MaxItems dw Maximum allowable entries (expands dynamically in LPOST)
12 Items dw Current number of items
14 CurPntr dw Item currently being added, deleted or edited.
16 ItemPntr dd Pointer to array of ITEMS
1A Reserved db (06)
20 MaxText dd Maximum size of ASCII buffer
24 TxtSize dd Space already used in buffer (Next avaliable position)
28 TxtPntr dd Pointer to ASCII buffer
2C Reserved dd
30 BasePntr dw (28) Array of pointer to first entry of that character
(00) First entry less than letter "A"
(01) - (26) "A" - "Z"
(27) First entry greater than letter "Z"
68 Reserved dd (04)
When bit 2 of Status is on, these values are pointers to parent (FileNme) or decendant (FileHandle)
78 FileNme dd ASCII pointer to filename associated with list
7C FileHandle dd Handle to file that was opened
= 80 <128> Bytes
LCREATE ENTRY EAX Bits 31 - 08 = Initial number of elements required
07 - 00 = Average size of each entry
EBX = Pointer LPARAM structure
EDX = Pointer to ASCII description of string
RETURN EAX = NULL if error, otherwise datestamp list was created
CPU P4
LMEM_FIXED equ 0h
LMEM_ZEROINIT equ 40h
NULL equ 0
MB_OK equ 0
MB_APPLMODAL equ 0
extern _GetSystemTime@4, _SystemTimeToFileTime@8, _LocalAlloc@8, _MessageBoxA@16
extern _LocalFree@4
global LCreate
extern TStamp
section .data
ErrCaption db 'MEMORY ALLOCATION', 0
ErrText db 'Cannot allocate memory in LCreate', 0
section .text
; ==========================================================================================================
; ENTRY: ECX Bits 00 - 07 = Average size of each entry
; 24 - 08 = Initial number of nodes
; EDX = Pointer to lists description string
; RETURN: EAX = NULL if process failed, otherwise time stamp returned by TStamp
; ----------------------------------------------------------------------------------------------------------
LCreate push esi
push edi
push ebp
mov ebp, esp ; Create empty procedure frame
; Setup stack with the 4 parameters required for error reporting
push MB_OK | MB_APPLMODAL
push ErrText
push ErrCaption
push NULL
; Populate stack with local variables passed by caller
push edx ; Arg3: Pointer to lists description
mov eax, ecx
mov al, cl ; Avg size of each entry
shr eax, 8
push eax ; Arg2: Initial number of nodes in list
imul ecx
push eax ; Arg1: Initial size of Ascii buffer
; As parameter table can be in stack, it needs be initialized to known values
xor eax, eax
mov ecx, eax
mov cl, 48 ; Size of LParam structure
mov edi, ebx
rep stosb ; Nulls to LParam.BasePntr
dec eax
mov cl, 56
rep stosb ; Fill LParam.BasePntr's with -1's
inc eax
mov cl, 24
rep stosb ; Fill remainder of table
; Alloc memory for ASCII buffer. Arg2 is already on stack to LocalAlloc
push LMEM_ZEROINIT | LMEM_FIXED
call _LocalAlloc@8
test eax, eax
jnz .LC01
add esp, 8 ; Align stack appropriately
jmp .Error
.LC01 mov [ebx+40], eax ; Save TxtPntr
sub esp, 4
pop dword [ebx+32] ; Save MaxText
mov eax, [esp] ; Get initial number of nodes
mov [ebx+16], ax ; Store in LParam.MaxItems
shl eax, 4 ; Shift as each nodes parameters are 16 bytes
push eax
push LMEM_ZEROINIT | LMEM_FIXED
call _LocalAlloc@8 ; Get pointer
test eax, eax
pop ecx ; Restore max item count
jnz .LC02
push dword [ebx+40] ; Get pointer to ASCII buffer
call _LocalFree@4
pop edx ; Waste last argument left on stack
jmp .Error
.LC02 mov [ebx+22], eax ; Store LParam.ItemPntr
mov edi, eax ; Set pointer for block moves
xor eax, eax
dec eax ; Set fill pattern
.LC03 stosw ; Set nodes status bits, (all on = never used]
add edi, 4 ; Bump to Prev & Next positions
stosd
add edi, 6 ; Point to beginning of next node
loop .LC03
pop edi ; Restore pointer to lists description
mov esi, edi
mov eax, ecx
dec ecx
repnz scasb ; Determine strings length
mov edi, [ebx+40] ; Get pointer to list ASCII buffer again
inc ecx
neg ecx ; ECX = Strings length include terminator
mov [ebx+36], ecx ; Store LParam.TxtSize
rep movsb ; Copy string to destination
call TStamp
mov dword [ebx+2], eax ; Save date stamp of lists creation
inc byte [ebx] ; Bump status bit 0 = 1 Table initialized and ready
jmp .Done
.Error call _MessageBoxA@16
xor eax, eax
.Done leave ; Kill procedure frame
pop edi ; Restore index registers
pop esi
ret
ABH = 171 bytes
Looks good TC, it would be helpful to many folks if you can post a working example a bit later.
As a request from some one, they would like a copy of this they can maintain in ML and it's design be STD call compliant so procedures can be called from "C".
; ==========================================================================================================
LL_ITEMS STRUCT
Status dw ? ; FF = Node never used
; When Bit3 of LL_PARAM status, then this associate node #
Posted dd ? ; Elapsed time in seconds since 1970-01-01
Prev dw ? ; Pointer to previous node number
Next dw ? ; Pointer to next node
Chars dw ? ; Number of characters in string
Pntr dd ? ; Offset in LL_PARAM.TxtPntr
LL_ITEMS ENDS
; ===========================================================================================================
LL_PARAM STRUCT
Status dw ? ; All bits ON = Empty, never used
; Bit 01 = List is active, ok to use
; Bit 02 = Data has changed since last load
Created dd ? ; Number of seconds since 1970-01-01
align 16
MaxItems dw ? ; Current space allocated to nodes
Items dw ? ; Number of items already in list
CurPntr dw ? ; Pointer to which is active node
ItemPntr dd ? ; Pointer to table
align 16
MaxText dd ? ; Size of ASCII buffer
TxtSize dd ? ; How much of it is already used
TxtPntr dd ? ; Pointer to buffer
align 16
; Base Pointer is an array of 28 words that points to the first element matching that letter
BasePntr dw 28 dup (?) ; Index 0 = Anything less than the letter 'A'
; 1 <> 26 'A' through 'Z'
; 27 = Anything greater than 'Z'
; Whenever one or the other is specified it is the pointer to that lists LL_PARAM
; When A parent record is deleted, it will delete all decendants
; Only when all decendants are deleted, will the parent be deleted.
Parent dd ? ; Many of these are related to one of parent
Child dd ? ; One of these is related to many of those
Padd dd ?, ? ; Res'vd for future use and to padd structure to 128 bytes
FileNme dd ? ; Pointer to ASCII filename
FileHandle dd ? ; Handle that is currently opened to this list
LL_PARAM ENDS
; ----------------------------------------------------------------------------------------------------------
DELIMITER equ '|'
CHAR_MASK equ 5FH
NULL equ 0
One of the major changes I made here was to remove error reporting. It will be the responsibility of the calling process to do whatever is required as even if this fails
it doesn't necessarily necessitate termination of application, whether it be CONSOLE or GUI.
.586P
.model flat, stdcall
option casemap:none
include LStructs.inc
.nolist
include windows.inc
include kernel32.inc
include user32.inc
include msvcrt.inc
.list
includelib kernel32.lib
includelib user32.lib
includelib msvcrt.lib
.code
; ==========================================================================================================
; ENTRY: Arg1 > AL = Average number of bytes / entry
; > Bits 31 - 08 Initial number of nodes
; Arg2 > Pointer to ASCII string that describes lists contents
; Arg3 > Pointer to LL_PARAM
; RETURNS: EAX = NULL if either memory region could not be created
; = TimeStamp if procedure succeeded, in otherwords !NULL.
; ----------------------------------------------------------------------------------------------------------
LCreate proc uses esi edi ebx Sizes:DWORD, ListDesc:DWORD, Param_Table:DWORD
; Initialize LPARAM buffer to initial values
xor ecx, ecx
mov cl, sizeof LL_PARAM ; Size of structure
xor eax, eax ; Fill pattern
mov edi, ebx ; Pointer to buffer
shr ecx, 2 ; Adjust size to represent number of dwords
rep stosd
lea edi, [ebx+LL_PARAM.BasePntr]
mov cl, sizeof LL_PARAM.BasePntr
shr ecx, 2 ; Adjust for number of dwords
dec eax ; Fill pattern to -1's
rep stosd
; Calculate buffer sizes based on values passed in Sizes
mov eax, Sizes ; Get values passed by caller
xor ecx, ecx
mov cl, al ; ECX = Average size of each entry
shr eax, 8 ; Shift initial node counter
push eax ; Will need this when nodes are created
; ASCII buffer is the larger of the two most often, so we will create it first.
imul ecx ; Determine intial number of bytes
push eax
push LMEM_FIXED or LMEM_ZEROINIT
call LocalAlloc ; Get pointer to memory
ASSUME ebx : PTR LL_PARAM
or eax, eax ; Did API return a pointer
jz Err
mov ebx, Param_Table ; Establish pointer to LL_PARAM
mov [ebx].TxtPntr, eax ; Save pointer
mov edi, eax
mov eax, [esp - 4] ; Get size of buffer
mov [ebx].MaxText, eax ; Save size of buffer
; Now we can move description string to destination. lstrlen & lstrcpy could have been used
; here, but after cleaning up stack, this uses just a little more space
push edi ; Save destination pointer
xor ecx, ecx
mov al, cl
mov edi, ListDesc ; Pointer to description passed by caller
dec ecx ; ECX = -1 so str length can be calculated
push edi ; Weill need this pointer again
repnz scasb ; Find EOS
not ecx ; String length including terminator
mov [ebx].TxtSize, ecx ; Save in talbe
pop esi
pop edi
dec ecx ; Restore pointers and transfer string
rep movsb
; Nodes table can be created now
mov eax, [esp] ; Get initial number of nodes calculated earlier
mov [ebx].MaxItems, ax
imul eax, sizeof LL_ITEMS
push eax
push LMEM_FIXED or LMEM_ZEROINIT
call LocalAlloc
.if eax
mov [ebx].ItemPntr, eax ; Save pointer
mov edi, eax
pop ecx ; Get number of nodes again
xor eax, eax
mov edx, eax
dec eax ; Establish fill pattern
mov dl, sizeof LL_ITEMS
; Loop through each of the nodes, initializing status, prev & Next values to -1's
@@: mov [edi], ax ; Save status
mov dword ptr [edi+LL_ITEMS.Prev], eax
add edi, edx
loop @B
; Only two fields left to initialize and that is datestamp & status
inc byte ptr [ebx] ; Set status to table active
lea eax, [ebx+LL_ITEMS.Posted]
push eax
call crt_time ; Number of seconds since 1970-01-01
; Allocating space for nodes failed, so we need to recover memory from ASCII buffer
.else
push dword ptr [ebx].TxtPntr ; Get address of ASCII buffer
call LocalFree ; recover memory
Err: xor eax, eax ; return NULL status
.endif
ASSUME ebx : NOTHING
ret
LCreate endp
end
The way I do things in NASM just got me in trouble
inc byte ptr [ebx] ; Set status to table active
lea eax, [ebx+LL_ITEMS.Posted]
push eax
call crt_time ; Number of seconds since 1970-01-01
Needs add esp, 4 ; So register are restore properly in epilogue
Note how in NASM code I preserve registers before procedure frame that way stack need not be aligned upon completion.