[libvirt] [PATCHv2 RESEND 1/5] viruuid.h/c: Util method for finding uuid patterns in some strings

[Manuel VIVES]

---
 src/libvirt_private.syms |    1 +
 src/util/viruuid.c       |   79 ++++++++++++++++++++++++++++++++++++++++++++++
 src/util/viruuid.h       |    1 +
 3 files changed, 81 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 35f0f1b..a6af540 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2080,6 +2080,7 @@ virValidateWWN;
 
 # util/viruuid.h
 virGetHostUUID;
+virSearchUuid;
 virSetHostUUIDStr;
 virUUIDFormat;
 virUUIDGenerate;
diff --git a/src/util/viruuid.c b/src/util/viruuid.c
index c5fa9a8..3786393 100644
--- a/src/util/viruuid.c
+++ b/src/util/viruuid.c
@@ -34,6 +34,7 @@
 #include <sys/stat.h>
 #include <time.h>
 #include <unistd.h>
+#include <regex.h>
 
 #include "c-ctype.h"
 #include "internal.h"
@@ -43,11 +44,14 @@
 #include "viralloc.h"
 #include "virfile.h"
 #include "virrandom.h"
+#include "virstring.h"
 
 #ifndef ENODATA
 # define ENODATA EIO
 #endif
 
+#define VIR_FROM_THIS VIR_FROM_NONE
+
 static unsigned char host_uuid[VIR_UUID_BUFLEN];
 
 static int
@@ -333,3 +337,78 @@ int virGetHostUUID(unsigned char *uuid)
 
     return ret;
 }
+
+
+/**
+ * virSearchUuid:
+ * Return the nth occurrence of a substring in sourceString which matches an uuid pattern
+ * If there is no substring, ret is not modified
+ *
+ * @sourceString: String to parse
+ * @occurrence: We will return the nth occurrence of uuid in substring, if equals to 0 (or negative), will return the first occurence
+ * @ret: nth occurrence substring matching an uuid pattern
+ * @code
+    char *source = "6853a496-1c10-472e-867a-8244937bd6f0 773ab075-4cd7-4fc2-8b6e-21c84e9cb391 bbb3c75c-d60f-43b0-b802-fd56b84a4222 60c04aa1-0375-4654-8d9f-e149d9885273 4548d465-9891-4c34-a184-3b1c34a26aa8";
+    char *ret1=NULL;
+    char *ret2=NULL;
+    char *ret3=NULL;
+    char *ret4=NULL;
+    virSearchUuid(source, 4,&ret1);  //ret1 = "60c04aa1-0375-4654-8d9f-e149d9885273"
+    virSearchUuid(source, 0,&ret2);  //ret2 = "6853a496-1c10-472e-867a-8244937bd6f0"
+    virSearchUuid(source, 1,&ret3);  //ret3 = "6853a496-1c10-472e-867a-8244937bd6f0"
+    virSearchUuid(source, -4,&ret4); //ret4 = "6853a496-1c10-472e-867a-8244937bd6f0"
+ * @endcode
+ */
+
+char **
+virSearchUuid(const char *sourceString, int occurrence,char **ret)
+{
+    int position = ((occurrence -1) > 0) ? (occurrence -1) : 0;
+
+    const char *uuidRegex = "([a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12})";
+    regex_t pregUuidBracket;
+    size_t i = 0;
+    size_t nmatch = 0;
+    regmatch_t *pmatch = NULL;
+    if (regcomp(&pregUuidBracket, uuidRegex, REG_EXTENDED) != 0) {
+        VIR_DEBUG("Error while compiling regular expression");
+        goto cleanup;
+    }
+    nmatch = pregUuidBracket.re_nsub;
+    if (VIR_ALLOC_N(pmatch, nmatch) != 0) {
+        virReportOOMError();
+        goto cleanup;
+    }
+    while (i < (position+1)) {
+        if (regexec(&pregUuidBracket, sourceString, nmatch, pmatch, 0) == 0) {
+            char *substring = NULL;
+            int start = pmatch[0].rm_so;
+            int end = pmatch[0].rm_eo;
+            size_t size = end - start;
+            if (VIR_ALLOC_N(substring, (size + 1)) != 0) {
+                virReportOOMError();
+                goto cleanup;
+            }
+            if (substring) {
+                if (virStrncpy(substring, &sourceString[start], size, size + 1)) {
+                    substring[size] = '\0';
+                    if (VIR_STRDUP(*ret, substring) < 0) {
+                        VIR_DEBUG("cannot duplicate %s", substring);
+                        goto cleanup;
+                    }
+                }
+                VIR_FREE(substring);
+            }
+            sourceString = &sourceString[end];
+        }
+        ++i;
+    }
+    regfree(&pregUuidBracket);
+    VIR_FREE(pmatch);
+    return ret;
+
+cleanup:
+    regfree(&pregUuidBracket);
+    VIR_FREE(pmatch);
+    return ret;
+}
diff --git a/src/util/viruuid.h b/src/util/viruuid.h
index bebd338..276e85f 100644
--- a/src/util/viruuid.h
+++ b/src/util/viruuid.h
@@ -40,4 +40,5 @@ int virUUIDParse(const char *uuidstr,
 const char *virUUIDFormat(const unsigned char *uuid,
                           char *uuidstr) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
+char ** virSearchUuid(const char *sourceString, int occurrence, char **ret);
 #endif /* __VIR_UUID_H__ */
-- 
1.7.10.4