Lệnh Shell chậm khi sử dụng đường ống, nhanh với tệp trung gian

19

Có ai hiểu sự khác biệt lớn này trong thời gian xử lý, khi sử dụng tệp trung gian hoặc khi sử dụng đường ống không? Tôi đang chuyển đổi tiff sang pdf bằng các công cụ tiêu chuẩn trên máy chủ nén debian mới. Một cách tiêu chuẩn để làm điều này là chuyển đổi sang ps trước.

Không có đường ống:

root@web5:~# time tiff2ps test.tif > test.ps

real    0m0.860s
user    0m0.744s
sys 0m0.112s

root@web5:~# time ps2pdf13 -sPAPERSIZE=a4 test.ps > test.pdf

real    0m0.667s
user    0m0.612s
sys 0m0.060s

Với đường ống:

root@web5:~# time tiff2ps test.tif | ps2pdf13 -sPAPERSIZE=a4 - > test.pdf

real    1m6.098s
user    0m15.861s
sys 0m50.9

Trong lệnh cuối cùng, quá trình gs luôn ở mức 100%.

Cập nhật :
Đây là một đầu ra bước cho thế hệ ps:

root@web5:~# strace tiff2ps test.tif > test.ps
execve("/usr/bin/tiff2ps", ["tiff2ps", "test.tif"], [/* 28 vars */]) = 0
brk(0)                                  = 0x1395000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a1937000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=21735, ...}) = 0
mmap(NULL, 21735, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fb5a1931000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/libtiff.so.4", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\200\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=405128, ...}) = 0
mmap(NULL, 2501416, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fb5a14b9000
mprotect(0x7fb5a151a000, 2093056, PROT_NONE) = 0
mmap(0x7fb5a1719000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x60000) = 0x7fb5a1719000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/libjpeg.so.62", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\3408\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=145048, ...}) = 0
mmap(NULL, 2240080, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fb5a1296000
mprotect(0x7fb5a12b9000, 2093056, PROT_NONE) = 0
mmap(0x7fb5a14b8000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7fb5a14b8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/libz.so.1", O_RDONLY)    = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260\"\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=93936, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a1930000
mmap(NULL, 2188976, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fb5a107f000
mprotect(0x7fb5a1096000, 2093056, PROT_NONE) = 0
mmap(0x7fb5a1295000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x16000) = 0x7fb5a1295000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/libm.so.6", O_RDONLY)        = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360>\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=530736, ...}) = 0
mmap(NULL, 2625768, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fb5a0dfd000
mprotect(0x7fb5a0e7d000, 2097152, PROT_NONE) = 0
mmap(0x7fb5a107d000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x80000) = 0x7fb5a107d000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240\355\1\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1437064, ...}) = 0
mmap(NULL, 3545160, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fb5a0a9b000
mprotect(0x7fb5a0bf4000, 2093056, PROT_NONE) = 0
mmap(0x7fb5a0df3000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x158000) = 0x7fb5a0df3000
mmap(0x7fb5a0df8000, 18504, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fb5a0df8000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a192f000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a192e000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a192d000
arch_prctl(ARCH_SET_FS, 0x7fb5a192e700) = 0
mprotect(0x7fb5a0df3000, 16384, PROT_READ) = 0
mprotect(0x7fb5a107d000, 4096, PROT_READ) = 0
mprotect(0x7fb5a1939000, 4096, PROT_READ) = 0
munmap(0x7fb5a1931000, 21735)           = 0
open("test.tif", O_RDONLY)              = 3
brk(0)                                  = 0x1395000
brk(0x13b6000)                          = 0x13b6000
read(3, "II*\0\10\0\0\0", 8)            = 8
fstat(3, {st_mode=S_IFREG|0644, st_size=1825656, ...}) = 0
mmap(NULL, 1825656, PROT_READ, MAP_SHARED, 3, 0) = 0x7fb5a176f000
open("/proc/meminfo", O_RDONLY)         = 4
fstat(4, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a1936000
read(4, "MemTotal:        2090844 kB\nMemF"..., 1024) = 1024
close(4)                                = 0
munmap(0x7fb5a1936000, 4096)            = 0
write(2, "TIFFReadDirectory: ", 19TIFFReadDirectory: )     = 19
write(2, "Warning, ", 9Warning, )                = 9
write(2, "test.tif: wrong data type 7 for "..., 59test.tif: wrong data type 7 for "RichTIFFIPTC"; tag ignored) = 59
write(2, ".\n", 2.
)                      = 2
gettimeofday({1334836895, 374666}, NULL) = 0
fstat(1, {st_mode=S_IFREG|0664, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a1936000
open("/etc/localtime", O_RDONLY)        = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=1892, ...}) = 0
fstat(4, {st_mode=S_IFREG|0644, st_size=1892, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb5a1935000
read(4, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0\4\0\0\0\0"..., 4096) = 1892
lseek(4, -1217, SEEK_CUR)               = 675
read(4, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0\6\0\0\0\0"..., 4096) = 1217
close(4)                                = 0
munmap(0x7fb5a1935000, 4096)            = 0
write(1, "%!PS-Adobe-3.0 EPSF-3.0\n%%Creato"..., 4096) = 4096
write(1, "fffffffffffffffffffffffffffff\nff"..., 4096) = 4096
write(1, "ffffffffffffffffffff\nfffffffffff"..., 4096) = 4096
write(1, "fffffffffff\nffffffffffffffffffff"..., 4096) = 4096
write(1, "ff\nfffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffff\nfffffff"..., 4096) = 4096

Đây là một đầu ra strace cho phiên bản đường ống: Thế hệ PS dường như chậm hơn nhiều khi đầu ra được dẫn vào ps2pdf13. 

root@web5:~# strace tiff2ps test.tif | ps2pdf13 -sPAPERSIZE=a4 - > test.pdf
execve("/usr/bin/tiff2ps", ["tiff2ps", "test.tif"], [/* 28 vars */]) = 0
brk(0)                                  = 0x1b97000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208bb1000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=21735, ...}) = 0
mmap(NULL, 21735, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f9208bab000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/libtiff.so.4", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\200\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=405128, ...}) = 0
mmap(NULL, 2501416, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9208733000
mprotect(0x7f9208794000, 2093056, PROT_NONE) = 0
mmap(0x7f9208993000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x60000) = 0x7f9208993000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/libjpeg.so.62", O_RDONLY) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\3408\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=145048, ...}) = 0
mmap(NULL, 2240080, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9208510000
mprotect(0x7f9208533000, 2093056, PROT_NONE) = 0
mmap(0x7f9208732000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7f9208732000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/libz.so.1", O_RDONLY)    = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260\"\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=93936, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208baa000
mmap(NULL, 2188976, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f92082f9000
mprotect(0x7f9208310000, 2093056, PROT_NONE) = 0
mmap(0x7f920850f000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x16000) = 0x7f920850f000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/libm.so.6", O_RDONLY)        = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360>\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=530736, ...}) = 0
mmap(NULL, 2625768, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9208077000
mprotect(0x7f92080f7000, 2097152, PROT_NONE) = 0
mmap(0x7f92082f7000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x80000) = 0x7f92082f7000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/libc.so.6", O_RDONLY)        = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\240\355\1\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1437064, ...}) = 0
mmap(NULL, 3545160, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f9207d15000
mprotect(0x7f9207e6e000, 2093056, PROT_NONE) = 0
mmap(0x7f920806d000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x158000) = 0x7f920806d000
mmap(0x7f9208072000, 18504, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f9208072000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208ba9000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208ba8000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208ba7000
arch_prctl(ARCH_SET_FS, 0x7f9208ba8700) = 0
mprotect(0x7f920806d000, 16384, PROT_READ) = 0
mprotect(0x7f92082f7000, 4096, PROT_READ) = 0
mprotect(0x7f9208bb3000, 4096, PROT_READ) = 0
munmap(0x7f9208bab000, 21735)           = 0
open("test.tif", O_RDONLY)              = 3
brk(0)                                  = 0x1b97000
brk(0x1bb8000)                          = 0x1bb8000
read(3, "II*\0\10\0\0\0", 8)            = 8
fstat(3, {st_mode=S_IFREG|0644, st_size=1825656, ...}) = 0
mmap(NULL, 1825656, PROT_READ, MAP_SHARED, 3, 0) = 0x7f92089e9000
open("/proc/meminfo", O_RDONLY)         = 4
fstat(4, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208bb0000
read(4, "MemTotal:        2090844 kB\nMemF"..., 1024) = 1024
close(4)                                = 0
munmap(0x7f9208bb0000, 4096)            = 0
write(2, "TIFFReadDirectory: ", 19TIFFReadDirectory: )     = 19
write(2, "Warning, ", 9Warning, )                = 9
write(2, "test.tif: wrong data type 7 for "..., 59test.tif: wrong data type 7 for "RichTIFFIPTC"; tag ignored) = 59
write(2, ".\n", 2.
)                      = 2
gettimeofday({1334836513, 114140}, NULL) = 0
fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208bb0000
open("/etc/localtime", O_RDONLY)        = 4
fstat(4, {st_mode=S_IFREG|0644, st_size=1892, ...}) = 0
fstat(4, {st_mode=S_IFREG|0644, st_size=1892, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f9208baf000
read(4, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\4\0\0\0\4\0\0\0\0"..., 4096) = 1892
lseek(4, -1217, SEEK_CUR)               = 675
read(4, "TZif2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0\6\0\0\0\0"..., 4096) = 1217
close(4)                                = 0
munmap(0x7f9208baf000, 4096)            = 0
write(1, "%!PS-Adobe-3.0 EPSF-3.0\n%%Creato"..., 4096) = 4096
write(1, "fffffffffffffffffffffffffffff\nff"..., 4096) = 4096
write(1, "ffffffffffffffffffff\nfffffffffff"..., 4096) = 4096
write(1, "fffffffffff\nffffffffffffffffffff"..., 4096) = 4096
write(1, "ff\nfffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
write(1, "ffffffffffffffffffffffffffffffff"..., 4096) = 4096
...etc...
linux  bash  scripting  shell-scripting  pipe 
— plang
nguồn
Là những tập tin lớn?
— Khaled
Không, hoàn toàn không: 1,8 MB cho tệp tiff.
— plang
2
@plang: Bạn đã thử stracequy trình gs chưa? Có lẽ nó đang xử lý tệp thành nhiều phần lớn hơn khi sử dụng tệp trung gian hoặc điều gì đó tương tự xảy ra ...
— Janne Pikkarainen
Bạn có thể cung cấp phiên bản cụ thể của Ghostscript không? gs -v
— ewwhite
1
Đây là tiff: sendspace.com/file/vqoxbs
— plang

Câu trả lời:

17

Chỉnh sửa: Tôi đã chạy tệp này với tệp nguồn của bạn trong môi trường của tôi và có kết quả như sau:

[root@xt ~]# time tiff2ps test.tif > test.ps
real    0m0.795s
user    0m0.659s
sys     0m0.135s

[root@xt ~]# time ps2pdf13 -sPAPERSIZE=a4 test.ps > test.pdf
real    0m0.592s
user    0m0.513s
sys     0m0.075s

[root@xt ~]# time tiff2ps test.tif | ps2pdf13 -sPAPERSIZE=a4 - > test2.pdf
real    0m13.110s
user    0m4.601s
sys     0m7.260s

Tôi đã thêm pvlệnh để xem những gì đang xảy ra. Đây là những gì đã xảy ra:

[root@xt ~]# time tiff2ps test.tif | pv | ps2pdf13 -sPAPERSIZE=a4 - > test2.pdf
50.5MB 0:00:12 [4.05MB/s] [                      <=>                                                               ]

real    0m13.934s
user    0m4.751s
sys     0m8.261s

50 Megabyte đầu ra Postcript được dẫn đến ps2pdf13lệnh! @janneb đã đúng ở chỗ đây là vấn đề đệm / ống. Tôi đã cố gắng tận dụng unbufferlệnh , nhưng Ghostscript không thích giả hành.

Có bất kỳ lý do bạn không thể sử dụng tiff2pdflệnh?

[root@xt ~]# time tiff2pdf -o test2.pdf test.tif

real    0m0.242s
user    0m0.176s
sys     0m0.064s
— ewwhite
nguồn
Có một sự khác biệt tôi có thể thấy, nhưng ít quan trọng hơn với tệp thử nghiệm 1,8 MB của tôi.
— plang
1
Xin chào, tôi nghĩ rằng bạn đã tìm thấy vấn đề. Cảm ơn! Tôi không biết tiff2pdf tồn tại. Nó hoạt động, rất nhanh, nhưng có một vấn đề: đầu ra lớn 26 MB, so với 356K với tiff2ps / ps2pdf13.
— plang
1
Chạy nó với nén jpeg (384K): tiff2pdf -j -o test.pdf test.tifhoặc nén ZIP (1.6M):tiff2pdf -z -o test3.pdf test.tif
— ewwhite
1
tiff2pdf với các tùy chọn "-j" sửa vấn đề kích thước.
— plang
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