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annotate bin/warc.py @ 141:1e5f15a1e9fa
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| author | Henry S. Thompson <ht@inf.ed.ac.uk> |
|---|---|
| date | Tue, 19 Oct 2021 12:56:14 +0000 |
| parents | e96d444b0f84 |
| children | d123ef7fdb82 |
| rev | line source |
|---|---|
| 138 | 1 #!/usr/bin/env python3 |
| 2 '''Stream a warc format file, invoking a callback on each part. | |
| 3 Callback can be limited by WARC-Type''' | |
|
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parents:
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diff
changeset
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4 import sys,os |
| 138 | 5 |
| 6 def warc(callback,types=['response']): | |
| 7 nb=0 | |
|
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parents:
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diff
changeset
|
8 stream=open(sys.argv[1],'rb',0) |
| 138 | 9 bufsize=128*1024*1024 |
| 10 buf=bytearray(128*1024*1024) | |
| 11 l=b'\r\n' | |
| 12 while True: | |
| 13 while l==b'\r\n': | |
| 14 l=stream.readline() | |
| 15 nb+=len(l) | |
| 16 if l!=b'WARC/1.0\r\n': | |
|
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Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
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17 if l==b'': |
| 138 | 18 return |
| 19 raise ValueError("Not a WARC file? At %s: %s[%s]"%(nb-len(l), | |
| 20 l.decode('latin-1'),len(l))) | |
| 21 wtype=None | |
| 22 length=None | |
| 23 while l!=b'\r\n': | |
| 24 l=stream.readline() | |
| 25 nb+=len(l) | |
| 26 if l.startswith(b'WARC-Type: '): | |
| 27 wtype = l[11:-2] | |
| 28 elif l.startswith(b'Content-Length: '): | |
| 29 length = int(l[16:]) | |
| 30 bv=memoryview(buf)[:length] | |
| 31 ii=0 | |
| 32 while True: | |
| 33 i=stream.readinto(bv) | |
| 34 ii+=i | |
| 35 if ii>=length: | |
| 36 break | |
| 37 bv=memoryview(buf)[ii:length] | |
| 38 if ii!=length: | |
| 39 raise ValueError("Chunk read losing, from %s got %s expected %s"%(nb,ii,length)) | |
| 40 nb+=length | |
| 41 if wtype in types: | |
|
139
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
42 callback(wtype,memoryview(buf[:length])) |
| 138 | 43 if whole and options.zipped: |
| 44 _output(bv) | |
| 45 return | |
| 46 gzip_chunk = io.BytesIO(bv) | |
| 47 uv=memoryview(buf)[length:] | |
| 48 with igzip.IGzipFile(fileobj=gzip_chunk) as gzip_fin: | |
| 49 ll=0 | |
| 50 while True: | |
| 51 l=gzip_fin.readinto(uv) | |
| 52 if not l: | |
| 53 break | |
| 54 ll+=l | |
| 55 cb=memoryview(uv)[:ll] | |
| 56 if whole: | |
| 57 _output(cb) | |
| 58 return | |
| 59 # Only output parts (0 = WARC header, 1 = HTTP header, 2 = body) that are wanted | |
| 60 state=0 | |
| 61 tr=None # Was this record truncated? | |
| 62 bl=None # for HTTP Content-Length for the length of the body? | |
| 63 with io.BytesIO(cb) as clear_text: | |
| 64 for L in clear_text: | |
| 65 if state==0: | |
| 66 # WARC header | |
| 67 if L.startswith(b"Content-Length: "): | |
| 68 wl=int(L[16:].rstrip()) | |
| 69 elif L.startswith(b"WARC-Truncated: "): | |
| 70 tr=L[16:].rstrip() | |
| 71 tr="EMPTY" if tr=="" else tr | |
| 72 elif L==b"" or L.startswith(b"\r"): # for idempotency | |
| 73 # Blank line, WARC header is finished | |
| 74 if not (options.headers or options.body): | |
| 75 return | |
| 76 state=1 | |
| 77 # Note we preserve the empty line | |
| 78 if options.warc: | |
| 79 _output(L) | |
| 80 continue | |
| 81 if state==1: | |
| 82 # HTTP header | |
| 83 wl -= len(L) | |
| 84 if not (L==b"" or L.startswith(b"\r")): | |
| 85 # Non-blank, it's a header | |
| 86 if bl is None and L.startswith(b"Content-Length: "): | |
| 87 bl=int(L[16:].rstrip()) | |
| 88 if options.headers: | |
| 89 _output(L) | |
| 90 else: | |
| 91 # Blank line, HTTP header is finished | |
| 92 if not options.body: | |
| 93 return | |
| 94 if options.headers: | |
| 95 _output(L) | |
| 96 state=2 | |
| 97 # The above is just for sanity, because we do _not_ | |
| 98 # continue with the outer loop, | |
| 99 # since we can now block-output the entire rest of the | |
| 100 # input buffer. | |
| 101 if bl is not None: | |
| 102 if bl!=wl: | |
| 103 print("length mismatch: %s %s %s here: %s given: %s trunc: %s"%\ | |
| 104 (length,offset,filename,wl,bl,tr),file=sys.stderr) | |
| 105 # HTTP body | |
| 106 balance=clear_text.tell() | |
| 107 #print(balance,bl,wl,ll,ll-balance,file=sys.stderr) | |
| 108 # Output whatever is left | |
| 109 _output(cb[balance:balance+wl]) | |
| 110 return | |
| 111 | |
| 112 OUT=open(sys.stdout.fileno(),'wb') | |
| 113 | |
|
139
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
114 import re |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
115 LMPAT=re.compile(b'^Last-Modified: (.*?)\r',re.MULTILINE) |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
116 |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
117 def showmeLMH(wtype,buf): |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
118 m=LMPAT.search(buf.tobytes(order='A')) |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
119 if m: |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
120 OUT.write(m[1]) |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
121 OUT.write(b'\n') |
|
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
122 |
| 138 | 123 def showme(wtype,buf): |
| 124 OUT.write(buf) | |
| 125 | |
|
139
e96d444b0f84
fixed bug(s) wrt large payload files
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
138
diff
changeset
|
126 warc(showmeLMH,[b'response']) |