This Module collects reader methods such as read_string that are specific to Biff8. This Module is likely to be expanded as Support for older Versions of Excel grows and methods get moved here for disambiguation.
Read more data into the Shared String Table. (see also: read_sst) This method only evaluates the header, the actual work is done in #_read_sst
# File lib/spreadsheet/excel/reader/biff8.rb, line 55 def continue_sst work, oppos, len pos = 0 if @incomplete_sst pos = continue_string_header work, oppos elsif !@incomplete_skip.nil? pos = @incomplete_skip @incomplete_skip = nil end @sst_offset[1] += len _read_sst work, oppos, pos end
When a String is too long for one Opcode, it is continued in a Continue Opcode. Excel may reconsider compressing the remainder of the string. This method appends the available remainder (decompressed if necessary) to the incomplete string.
# File lib/spreadsheet/excel/reader/biff8.rb, line 15 def continue_string work, incomplete_string=@incomplete_string opts, _ = work.unpack 'C' wide = opts & 1 head, chars = incomplete_string owing = chars - head.size / 2 size = owing * (wide + 1) string = work[1, size] if wide == 0 string = wide string end head << string if head.size >= chars * 2 @incomplete_string = nil end size + 1 end
When a String is too long for one Opcode, it is continued in a Continue Opcode. Excel may reconsider compressing the remainder of the string. This method only evaluates the header and registers the address of the continuation with the previous SstEntry.
# File lib/spreadsheet/excel/reader/biff8.rb, line 36 def continue_string_header work, oppos opts, _ = work.unpack 'C' wide = opts & 1 owing = @incomplete_sst.continued_chars size = [work.size, owing * (1 + wide) + 1].min chars = (size - 1) / (1 + wide) skip = size @incomplete_sst.continue oppos + OPCODE_SIZE, size, chars unless @incomplete_sst.continued? @workbook.add_shared_string @incomplete_sst skip += @incomplete_skip @incomplete_sst = nil @incomplete_skip = nil end skip end
Store the offset of extsst, so we can write a new extsst when the sst has changed
# File lib/spreadsheet/excel/reader/biff8.rb, line 73 def read_extsst work, pos, len @workbook.offsets.store :extsst, [pos, len] end
# File lib/spreadsheet/excel/reader/biff8.rb, line 164 def read_range_address_list work, len # Cell range address, BIFF8: # Offset Size Contents # 0 2 Index to first row # 2 2 Index to last row # 4 2 Index to first column # 6 2 Index to last column # ! In several cases, BIFF8 still writes the BIFF2-BIFF5 format of a cell range address # (using 8-bit values for the column indexes). This will be mentioned at the respective place. # offset = 0, results = [] return results if len < 2 count = work[0..1].unpack('v').first offset = 2 count.times do |i| results << work[offset...offset+8].unpack('v4') offset += 8 end results end
Read the Shared String Table present in all Biff8 Files. This method only evaluates the header, the actual work is done in #_read_sst
# File lib/spreadsheet/excel/reader/biff8.rb, line 79 def read_sst work, pos, len # Offset Size Contents # 0 4 Total number of strings in the workbook (see below) # 4 4 Number of following strings (nm) # 8 var. List of nm Unicode strings, 16-bit string length (➜ 3.4) _, @sst_size = work.unpack 'V2' @sst_offset = [pos, len] @workbook.offsets.store :sst, @sst_offset _read_sst work, pos, 8 end
Read a string from the Spreadsheet, such as a Worksheet- or Font-Name, or a Number-Format. See also read_string_header and read_string_body
# File lib/spreadsheet/excel/reader/biff8.rb, line 92 def read_string work, count_length=1 # Offset Size Contents # 0 1 or 2 Length of the string (character count, ln) # 1 or 2 1 Option flags: # Bit Mask Contents # 0 0x01 Character compression (ccompr): # 0 = Compressed (8-bit characters) # 1 = Uncompressed (16-bit characters) # 2 0x04 Asian phonetic settings (phonetic): # 0 = Does not contain Asian phonetic settings # 1 = Contains Asian phonetic settings # 3 0x08 Rich-Text settings (richtext): # 0 = Does not contain Rich-Text settings # 1 = Contains Rich-Text settings # [2 or 3] 2 (optional, only if richtext=1) # Number of Rich-Text formatting runs (rt) # [var.] 4 (optional, only if phonetic=1) # Size of Asian phonetic settings block (in bytes, sz) # var. ln Character array (8-bit characters # or 2∙ln or 16-bit characters, dependent on ccompr) # [var.] 4∙rt (optional, only if richtext=1) # List of rt formatting runs (➜ 3.2) # [var.] sz (optional, only if phonetic=1) # Asian Phonetic Settings Block (➜ 3.4.2) chars, offset, wide, _, _, available, owing, _ = read_string_header work, count_length string, _ = read_string_body work, offset, available, wide > 0 if owing > 0 @incomplete_string = [string, chars] end string end
Read the body of a string. Returns the String (decompressed if necessary) and the available data (unchanged).
# File lib/spreadsheet/excel/reader/biff8.rb, line 126 def read_string_body work, offset, available, wide data = work[offset, available] string = wide ? data : wide(data) [string, data] end
Read the header of a string. Returns the following information in an Array:
The total number of characters in the string
The offset of the actual string data (= the length of this header in bytes)
Whether or not the string was compressed (0/1)
Whether or not the string contains asian phonetic settings (0/1)
Whether or not the string contains richtext formatting (0/1)
The number of bytes containing characters in this chunk of data
The number of characters missing from this chunk of data and expected to follow in a Continue Opcode
# File lib/spreadsheet/excel/reader/biff8.rb, line 141 def read_string_header work, count_length=1, offset=0 fmt = count_length == 1 ? 'C2' : 'vC' chars, opts = work[offset, 1 + count_length].unpack fmt wide = opts & 1 phonetic = (opts >> 2) & 1 richtext = (opts >> 3) & 1 size = chars * (wide + 1) skip = 0 if richtext > 0 runs, = work[offset + 1 + count_length, 2].unpack 'v' skip = 4 * runs end if phonetic > 0 psize, = work[offset + 1 + count_length + richtext * 2, 4].unpack 'V' skip += psize end flagsize = 1 + count_length + richtext * 2 + phonetic * 4 avbl = [work.size - offset, flagsize + size].min have_chrs = (avbl - flagsize) / (1 + wide) owing = chars - have_chrs [chars, flagsize, wide, phonetic, richtext, avbl, owing, skip] end
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