Re: [libvirt] [PATCHv2 04/13] virbuf: add auto-indentation support

Rather than having to adjust all callers in a chain to deal with indentation, it is nicer to have virBuffer do auto-indentation. * src/util/buf.h (_virBuffer): Increase size. (virBufferAdjustIndent, virBufferGetIndent): New prototypes. * src/libvirt_private.syms (buf.h): Export new functions. * src/util/buf.c (virBufferAdjustIndent, virBufferGetIndent): New functions. (virBufferSetError, virBufferAdd, virBufferAddChar) (virBufferVasprintf, virBufferStrcat, virBufferURIEncodeString): Implement auto-indentation. * tests/virbuftest.c (testBufAutoIndent): Test it. (testBufInfiniteLoop): Don't rely on internals. Idea by Daniel P. Berrange. --- src/libvirt_private.syms | 2 + src/util/buf.c | 138 ++++++++++++++++++++++++++++----------------- src/util/buf.h | 12 +++- tests/virbuftest.c | 85 +++++++++++++++++++++++++--- 4 files changed, 172 insertions(+), 65 deletions(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index c2a3fab..695ff33 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -22,12 +22,14 @@ virBitmapString; # buf.h virBufferAdd; virBufferAddChar; +virBufferAdjustIndent; virBufferAsprintf; virBufferContentAndReset; virBufferError; virBufferEscapeSexpr; virBufferEscapeString; virBufferFreeAndReset; +virBufferGetIndent; virBufferStrcat; virBufferURIEncodeString; virBufferUse; diff --git a/src/util/buf.c b/src/util/buf.c index 98bb681..b409de4 100644 --- a/src/util/buf.c +++ b/src/util/buf.c @@ -28,6 +28,7 @@ struct _virBuffer { unsigned int size; unsigned int use; unsigned int error; /* errno value, or -1 for usage error */ + int indent; char *content; }; @@ -44,10 +45,54 @@ virBufferSetError(virBufferPtr buf, int error) VIR_FREE(buf->content); buf->size = 0; buf->use = 0; + buf->indent = 0; buf->error = error; } /** + * virBufferAdjustIndent: + * @buf: the buffer + * @indent: adjustment to make + * + * Alter the auto-indent value by adding indent (positive to increase, + * negative to decrease). Automatic indentation is performed by all + * additive functions when the existing buffer is empty or ends with a + * newline (however, note that no indentation is added if you append a + * string with an embedded newline). If @indent would cause overflow, + * the buffer error indicator is set. + */ +void +virBufferAdjustIndent(virBufferPtr buf, int indent) +{ + if (!buf || buf->error) + return; + if (indent> 0 ? INT_MAX - indent< buf->indent

+ : buf->indent< -indent) { + virBufferSetError(buf, -1); + return; + } + buf->indent += indent; +} + +/** + * virBufferGetIndent: + * @buf: the buffer + * @dynamic: if false, return set value; if true, return 0 unless next + * append would be affected by auto-indent + * + * Return the current auto-indent value, or -1 if there has been an error. + */ +int +virBufferGetIndent(const virBufferPtr buf, bool dynamic) +{ + if (!buf || buf->error) + return -1; + if (dynamic&& buf->use&& buf->content[buf->use - 1] != '\n') + return 0; + return buf->indent; +} + +/** * virBufferGrow: * @buf: the buffer * @len: the minimum free size to allocate on top of existing used space @@ -79,35 +124,39 @@ virBufferGrow(virBufferPtr buf, unsigned int len) /** * virBufferAdd: - * @buf: the buffer to add to - * @str: the string - * @len: the number of bytes to add + * @buf: the buffer to append to + * @str: the string + * @len: the number of bytes to add, or -1 * - * Add a string range to an XML buffer. if len == -1, the length of - * str is recomputed to the full string. + * Add a string range to an XML buffer. If @len == -1, the length of + * str is recomputed to the full string. Auto indentation may be applied. * */ void virBufferAdd(const virBufferPtr buf, const char *str, int len) { unsigned int needSize; + int indent; - if ((str == NULL) || (buf == NULL) || (len == 0)) + if (!str || !buf || (len == 0&& buf->indent == 0)) return; if (buf->error) return; + indent = virBufferGetIndent(buf, true); + if (len< 0) len = strlen(str); - needSize = buf->use + len + 2; + needSize = buf->use + indent + len + 2; if (needSize> buf->size&& virBufferGrow(buf, needSize - buf->use)< 0) return; - memcpy (&buf->content[buf->use], str, len); - buf->use += len; + memset(&buf->content[buf->use], ' ', indent); + memcpy(&buf->content[buf->use + indent], str, len); + buf->use += indent + len; buf->content[buf->use] = '\0'; } @@ -116,27 +165,13 @@ virBufferAdd(const virBufferPtr buf, const char *str, int len) * @buf: the buffer to append to * @c: the character to add * - * Add a single character 'c' to a buffer. + * Add a single character 'c' to a buffer. Auto indentation may be applied. * */ void -virBufferAddChar (virBufferPtr buf, char c) +virBufferAddChar(virBufferPtr buf, char c) { - unsigned int needSize; - - if (buf == NULL) - return; - - if (buf->error) - return; - - needSize = buf->use + 2; - if (needSize> buf->size&& - virBufferGrow (buf, needSize - buf->use)< 0) - return; - - buf->content[buf->use++] = c; - buf->content[buf->use] = '\0'; + virBufferAdd(buf,&c, 1); } /** @@ -218,7 +253,7 @@ virBufferUse(const virBufferPtr buf) * @format: the format * @...: the variable list of arguments * - * Do a formatted print to an XML buffer. + * Do a formatted print to an XML buffer. Auto indentation may be applied. */ void virBufferAsprintf(virBufferPtr buf, const char *format, ...) @@ -231,11 +266,11 @@ virBufferAsprintf(virBufferPtr buf, const char *format, ...) /** * virBufferVasprintf: - * @buf: the buffer to dump + * @buf: the buffer to append to * @format: the format * @argptr: the variable list of arguments * - * Do a formatted print to an XML buffer. + * Do a formatted print to an XML buffer. Auto indentation may be applied. */ void virBufferVasprintf(virBufferPtr buf, const char *format, va_list argptr) @@ -249,6 +284,9 @@ virBufferVasprintf(virBufferPtr buf, const char *format, va_list argptr) if (buf->error) return; + if (buf->indent) + virBufferAdd(buf, "", -1); + if (buf->size == 0&& virBufferGrow(buf, 100)< 0) return; @@ -287,10 +325,12 @@ virBufferVasprintf(virBufferPtr buf, const char *format, va_list argptr) * virBufferEscapeString: * @buf: the buffer to append to * @format: a printf like format string but with only one %s parameter - * @str: the string argument which need to be escaped + * @str: the string argument which needs to be escaped * - * Do a formatted print with a single string to an XML buffer. The string - * is escaped to avoid generating a not well-formed XML instance. + * Do a formatted print with a single string to an XML buffer. The + * string is escaped for use in XML. If @str is NULL, nothing is + * added (not even the rest of @format). Auto indentation may be + * applied. */ void virBufferEscapeString(virBufferPtr buf, const char *format, const char *str) @@ -372,11 +412,12 @@ virBufferEscapeString(virBufferPtr buf, const char *format, const char *str) * virBufferEscapeSexpr: * @buf: the buffer to append to * @format: a printf like format string but with only one %s parameter - * @str: the string argument which need to be escaped + * @str: the string argument which needs to be escaped * - * Do a formatted print with a single string to an sexpr buffer. The string - * is escaped to avoid generating a sexpr that xen will choke on. This - * doesn't fully escape the sexpr, just enough for our code to work. + * Do a formatted print with a single string to an sexpr buffer. The + * string is escaped to avoid generating a sexpr that xen will choke + * on. This doesn't fully escape the sexpr, just enough for our code + * to work. Auto indentation may be applied. */ void virBufferEscapeSexpr(virBufferPtr buf, @@ -431,7 +472,7 @@ virBufferEscapeSexpr(virBufferPtr buf, * * Append the string to the buffer. The string will be URI-encoded * during the append (ie any non alpha-numeric characters are replaced - * with '%xx' hex sequences). + * with '%xx' hex sequences). Auto indentation may be applied. */ void virBufferURIEncodeString(virBufferPtr buf, const char *str) @@ -447,6 +488,9 @@ virBufferURIEncodeString(virBufferPtr buf, const char *str) if (buf->error) return; + if (buf->indent) + virBufferAdd(buf, "", -1); + for (p = str; *p; ++p) { if (c_isalnum(*p)) grow_size++; @@ -454,7 +498,7 @@ virBufferURIEncodeString(virBufferPtr buf, const char *str) grow_size += 3; /* %ab */ } - if (virBufferGrow (buf, grow_size)< 0) + if (virBufferGrow(buf, grow_size)< 0) return; for (p = str; *p; ++p) { @@ -476,7 +520,8 @@ virBufferURIEncodeString(virBufferPtr buf, const char *str) * @buf: the buffer to append to * @...: the variable list of strings, the last argument must be NULL * - * Concatenate strings to an XML buffer. + * Concatenate strings to an XML buffer. Auto indentation may be applied + * after each string argument. */ void virBufferStrcat(virBufferPtr buf, ...) @@ -488,18 +533,7 @@ virBufferStrcat(virBufferPtr buf, ...) return; va_start(ap, buf); - - while ((str = va_arg(ap, char *)) != NULL) { - unsigned int len = strlen(str); - unsigned int needSize = buf->use + len + 2; - - if (needSize> buf->size) { - if (virBufferGrow(buf, needSize - buf->use)< 0) - break; - } - memcpy(&buf->content[buf->use], str, len); - buf->use += len; - buf->content[buf->use] = 0; - } + while ((str = va_arg(ap, char *)) != NULL) + virBufferAdd(buf, str, -1); va_end(ap); } diff --git a/src/util/buf.h b/src/util/buf.h index 42a5044..08cb727 100644 --- a/src/util/buf.h +++ b/src/util/buf.h @@ -24,15 +24,16 @@ typedef struct _virBuffer virBuffer; typedef virBuffer *virBufferPtr; # ifndef __VIR_BUFFER_C__ -# define VIR_BUFFER_INITIALIZER { 0, 0, 0, NULL } +# define VIR_BUFFER_INITIALIZER { 0, 0, 0, 0, NULL } -/* This struct must be kept in syn with the real struct +/* This struct must be kept in sync with the real struct in the buf.c impl file */ struct _virBuffer { unsigned int a; unsigned int b; unsigned int c; - char *d; + int d; + char *e; }; # endif @@ -55,6 +56,9 @@ void virBufferEscapeSexpr(virBufferPtr buf, const char *format, void virBufferURIEncodeString(virBufferPtr buf, const char *str); # define virBufferAddLit(buf_, literal_string_) \ - virBufferAdd (buf_, "" literal_string_ "", sizeof literal_string_ - 1) + virBufferAdd(buf_, "" literal_string_ "", sizeof literal_string_ - 1) + +void virBufferAdjustIndent(virBufferPtr buf, int indent); +int virBufferGetIndent(const virBufferPtr buf, bool dynamic); #endif /* __VIR_BUFFER_H__ */ diff --git a/tests/virbuftest.c b/tests/virbuftest.c index 01db313..2f94e1c 100644 --- a/tests/virbuftest.c +++ b/tests/virbuftest.c @@ -20,7 +20,7 @@ struct testInfo { int doEscape; }; -static int testBufInfiniteLoop(const void *data ATTRIBUTE_UNUSED) +static int testBufInfiniteLoop(const void *data) { virBuffer bufinit = VIR_BUFFER_INITIALIZER; virBufferPtr buf =&bufinit; @@ -28,18 +28,13 @@ static int testBufInfiniteLoop(const void *data ATTRIBUTE_UNUSED) int ret = -1; const struct testInfo *info = data; - /* This relies of virBuffer internals, so may break if things change - * in the future */ virBufferAddChar(buf, 'a'); - if (buf->a != 1002 || buf->b != 1) { - TEST_ERROR("Buf was not expected size, size=%d use=%d\n", - buf->a, buf->b); - goto out; - } /* - * Infinite loop triggers if: + * Infinite loop used to trigger if: * (strlen + 1> 1000)&& (strlen == buf-size - buf-use - 1) + * which was the case after the above addchar at the time of the bug. + * This test is a bit fragile, since it relies on virBuffer internals. */ if (virAsprintf(&addstr, "%*s", buf->a - buf->b - 1, "a")< 0) { goto out; @@ -63,6 +58,77 @@ out: return ret; } +static int testBufAutoIndent(const void *data ATTRIBUTE_UNUSED) +{ + virBuffer bufinit = VIR_BUFFER_INITIALIZER; + virBufferPtr buf =&bufinit; + const char expected[] = + " 1\n 2\n 3\n 4\n 5\n 6\n 7\n&amp;\n 8\n 9\n"; + char *result = NULL; + int ret = 0; + + if (virBufferGetIndent(buf, false) != 0 || + virBufferGetIndent(buf, true) != 0) { + TEST_ERROR("Wrong indentation"); + ret = -1; + } + virBufferAdjustIndent(buf, 3); + if (virBufferGetIndent(buf, false) != 3 || + virBufferGetIndent(buf, true) != 3 || + virBufferError(buf)) { + TEST_ERROR("Wrong indentation"); + ret = -1; + } + virBufferAdjustIndent(buf, -2); + if (virBufferGetIndent(buf, false) != 1 || + virBufferGetIndent(buf, true) != 1 || + virBufferError(buf)) { + TEST_ERROR("Wrong indentation"); + ret = -1; + }

+ virBufferAdjustIndent(buf, -2);

+ if (virBufferGetIndent(buf, false) != -1 || + virBufferGetIndent(buf, true) != -1 || + virBufferError(buf) != -1) { + TEST_ERROR("Usage error not flagged"); + ret = -1; + } + virBufferFreeAndReset(buf); + if (virBufferGetIndent(buf, false) != 0 || + virBufferGetIndent(buf, true) != 0 || + virBufferError(buf)) { + TEST_ERROR("Reset didn't clear indentation"); + ret = -1; + } + virBufferAdjustIndent(buf, 2); + virBufferAddLit(buf, "1"); + if (virBufferGetIndent(buf, false) != 2 || + virBufferGetIndent(buf, true) != 0) { + TEST_ERROR("Wrong indentation"); + ret = -1; + } + virBufferAddLit(buf, "\n"); + virBufferAdd(buf, "" "2\n", -1); /* Extra "" appeases syntax-check */ + virBufferAddChar(buf, '3'); + virBufferAddChar(buf, '\n'); + virBufferAsprintf(buf, "%d", 4); + virBufferAsprintf(buf, "%c", '\n'); + virBufferStrcat(buf, "5", "\n", "6\n", NULL); + virBufferEscapeString(buf, "%s\n", "7"); + virBufferEscapeString(buf, "%s\n", "&"); + virBufferEscapeSexpr(buf, "%s", "8\n"); + virBufferURIEncodeString(buf, "9"); + virBufferAddChar(buf, '\n'); + + result = virBufferContentAndReset(buf); + if (!result || STRNEQ(result, expected)) { + virtTestDifference(stderr, expected, result); + ret = -1; + } + VIR_FREE(result); + return ret; +} + static int mymain(void) { @@ -78,6 +144,7 @@ mymain(void) DO_TEST("EscapeString infinite loop", testBufInfiniteLoop, 1); DO_TEST("VSprintf infinite loop", testBufInfiniteLoop, 0); + DO_TEST("Auto-indentation", testBufAutoIndent, 0); return(ret==0 ? EXIT_SUCCESS : EXIT_FAILURE); }