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[PATCH 03/16] vcs-svn: make buffer_copy_bytes return length read

From
David Barr <david.barr@cordelta.com>
Date
Mar 19, 2011, 07:20 UTC
Message-ID
<1300519254-20201-4-git-send-email-david.barr@cordelta.com>
In-Reply-To
<1300519254-20201-1-git-send-email-david.barr@cordelta.com>
From: Jonathan Nieder <jrnieder@gmail.com>

Currently buffer_copy_bytes does not report to its caller whether it encountered an early end of file.

Add a return value representing the number of bytes read (but not the number of bytes copied). This way all three unusual conditions can be distinguished: input error with buffer_ferror, output error with ferror(outfile), early end of input by checking the return value.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
---
 vcs-svn/line_buffer.c |   18 +++++++++---------
 vcs-svn/line_buffer.h |    3 ++-
 2 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/vcs-svn/line_buffer.c b/vcs-svn/line_buffer.c
index a78c5d8..08d7cae 100644
--- a/vcs-svn/line_buffer.c
+++ b/vcs-svn/line_buffer.c
@@ -104,20 +104,20 @@ void buffer_read_binary(struct line_buffer *buf,
 	strbuf_fread(sb, size, buf->infile);
 }
 
-void buffer_copy_bytes(struct line_buffer *buf, off_t len)
+off_t buffer_copy_bytes(struct line_buffer *buf, off_t nbytes)
 {
 	char byte_buffer[COPY_BUFFER_LEN];
-	off_t in;
-	while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
-		in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
+	off_t done = 0;
+	while (done < nbytes && !feof(buf->infile) && !ferror(buf->infile)) {
+		off_t len = nbytes - done;
+		off_t in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
 		in = fread(byte_buffer, 1, in, buf->infile);
-		len -= in;
+		done += in;
 		fwrite(byte_buffer, 1, in, stdout);
-		if (ferror(stdout)) {
-			buffer_skip_bytes(buf, len);
-			return;
-		}
+		if (ferror(stdout))
+			return done + buffer_skip_bytes(buf, nbytes - done);
 	}
+	return done;
 }
 
 off_t buffer_skip_bytes(struct line_buffer *buf, off_t nbytes)
diff --git a/vcs-svn/line_buffer.h b/vcs-svn/line_buffer.h
index 7d10f9c..f5c468a 100644
--- a/vcs-svn/line_buffer.h
+++ b/vcs-svn/line_buffer.h
@@ -26,7 +26,8 @@ char *buffer_read_line(struct line_buffer *buf);
 char *buffer_read_string(struct line_buffer *buf, uint32_t len);
 int buffer_read_char(struct line_buffer *buf);
 void buffer_read_binary(struct line_buffer *buf, struct strbuf *sb, uint32_t len);
-void buffer_copy_bytes(struct line_buffer *buf, off_t len);
+/* Returns number of bytes read (not necessarily written). */
+off_t buffer_copy_bytes(struct line_buffer *buf, off_t len);
 off_t buffer_skip_bytes(struct line_buffer *buf, off_t len);
 
 #endif
-- 
1.7.3.2.846.gf4b062
Previous: David BarrNext: David Barr
Message 24 of 72 in “vcs-svn: purge obsolete data structures and code”
  1. David BarrMar 19, 2011
  2. 1/9 vcs-svn: pass paths through to fast-importDavid Barr, Mar 19, 2011
  3. Jonathan NiederMar 19, 2011
  4. 2/9 vcs-svn: avoid using ls command twiceDavid Barr, Mar 19, 2011
  5. Jonathan NiederMar 19, 2011
  6. 3/9 vcs-svn: implement perfect hash for node-prop keysDavid Barr, Mar 19, 2011
  7. Jonathan NiederMar 19, 2011
  8. 1/3 vcs-svn: implement perfect hash for node-prop keysDavid Barr, Mar 21, 2011
  9. 2/3 vcs-svn: implement perfect hash for top-level keysDavid Barr, Mar 21, 2011
  10. 3/3 vcs-svn: use switch rather than cascading ifsDavid Barr, Mar 21, 2011
  11. [PATCHv2] vcs-svn: use switch rather than cascading ifsDavid Barr, Mar 21, 2011
  12. 4/9 vcs-svn: implement perfect hash for top-level keysDavid Barr, Mar 19, 2011
  13. Jonathan NiederMar 19, 2011
  14. 5/9 vcs-svn: factor out usage of string_poolDavid Barr, Mar 19, 2011
  15. Jonathan NiederMar 19, 2011
  16. 6/9 vcs-svn: drop string_poolDavid Barr, Mar 19, 2011
  17. 7/9 vcs-svn: drop trp.hDavid Barr, Mar 19, 2011
  18. 8/9 vcs-svn: drop obj_pool.hDavid Barr, Mar 19, 2011
  19. 9/9 vcs-svn: use strchr to find RFC822 delimiterDavid Barr, Mar 19, 2011
  20. Jonathan NiederMar 19, 2011
  21. vcs-svn: integrate support for text deltasDavid Barr, Mar 19, 2011
  22. 01/16 vcs-svn: improve support for reading large filesDavid Barr, Mar 19, 2011
  23. 02/16 vcs-svn: make buffer_skip_bytes return length readDavid Barr, Mar 19, 2011
  24. 03/16 vcs-svn: make buffer_copy_bytes return length readDavid Barr, Mar 19, 2011
  25. 04/16 vcs-svn: improve reporting of input errorsDavid Barr, Mar 19, 2011
  26. 05/16 vcs-svn: learn to maintain a sliding view of a fileDavid Barr, Mar 19, 2011
  27. 06/16 vcs-svn: skeleton of an svn delta parserDavid Barr, Mar 19, 2011
  28. Jonathan NiederMar 28, 2011
  29. 07/16 vcs-svn: parse svndiff0 window headerDavid Barr, Mar 19, 2011
  30. 08/16 vcs-svn: read the preimage when applying deltasDavid Barr, Mar 19, 2011
  31. 09/16 vcs-svn: read inline data from deltasDavid Barr, Mar 19, 2011
  32. 10/16 vcs-svn: read instructions from deltasDavid Barr, Mar 19, 2011
  33. 11/16 vcs-svn: implement copyfrom_data delta instructionDavid Barr, Mar 19, 2011
  34. 12/16 vcs-svn: verify that deltas consume all inline dataDavid Barr, Mar 19, 2011
  35. 13/16 vcs-svn: let deltas use data from postimageDavid Barr, Mar 19, 2011
  36. 14/16 vcs-svn: let deltas use data from preimageDavid Barr, Mar 19, 2011
  37. 15/16 vcs-svn: microcleanup in svndiff0 window-reading codeDavid Barr, Mar 19, 2011
  38. 16/16 vcs-svn: implement text-delta handlingDavid Barr, Mar 19, 2011
  39. Jonathan NiederMar 28, 2011
  40. David BarrMar 28, 2011
  41. 00/11 vcs-svn: purge obsolete data structures and codeDavid Barr, Mar 21, 2011
  42. 01/11 vcs-svn: use strbuf for revision logDavid Barr, Mar 21, 2011
  43. 02/11 vcs-svn: pass paths through to fast-importDavid Barr, Mar 21, 2011
  44. 03/11 vcs-svn: avoid using ls command twiceDavid Barr, Mar 21, 2011
  45. 04/11 vcs-svn: implement perfect hash for node-prop keysDavid Barr, Mar 21, 2011
  46. 05/11 vcs-svn: implement perfect hash for top-level keysDavid Barr, Mar 21, 2011
  47. 06/11 vcs-svn: use switch rather than cascading ifsDavid Barr, Mar 21, 2011
  48. 07/11 vcs-svn: factor out usage of string_poolDavid Barr, Mar 21, 2011
  49. 08/11 vcs-svn: drop string_poolDavid Barr, Mar 21, 2011
  50. =??q?=5BPATCH=2009/11=5D=20vcs-svn=3A=20drop=20trp=2Eh?=David Barr, Mar 21, 2011
  51. 10/11 vcs-svn: drop obj_pool.hDavid Barr, Mar 21, 2011
  52. 11/11 vcs-svn: use strchr to find RFC822 delimiterDavid Barr, Mar 21, 2011
  53. [PULL svn-fe] vcs-svn: simplifications, error handling improvementsJonathan Nieder, Mar 23, 2011
  54. Junio C HamanoMar 23, 2011
  55. Junio C HamanoMar 23, 2011
  56. Jonathan NiederMar 26, 2011
  57. t0081-line-buffer.sh hangs (Re: [PULL svn-fe] vcs-svn: simplifications, error handling improvements)Jonathan Nieder, Mar 26, 2011
  58. David BarrMar 23, 2011
  59. fixup! vcs-svn: improve reporting of input errorsDavid Barr, Mar 24, 2011
  60. Jonathan NiederMar 25, 2011
  61. 0/4 vcs-svn: null bytes in propertiesJonathan Nieder, Mar 25, 2011
  62. 1/4 vcs-svn: make reading of properties binary-safeJonathan Nieder, Mar 25, 2011
  63. tbMar 28, 2011
  64. Jonathan NiederMar 28, 2011
  65. Torsten BögershausenMar 28, 2011
  66. Jonathan NiederMar 28, 2011
  67. 2/4 vcs-svn: remove buffer_read_stringJonathan Nieder, Mar 25, 2011
  68. 3/4 vcs-svn: avoid unnecessary copying of log message and authorJonathan Nieder, Mar 25, 2011
  69. 4/4 vcs-svn: handle log message with embedded null bytesJonathan Nieder, Mar 25, 2011
  70. Jonathan NiederMar 26, 2011
  71. Junio C HamanoMar 26, 2011
  72. vcs-svn: add missing cast to printf argumentJonathan Nieder, Mar 28, 2011

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