XRootD
XrdCksLoader Class Reference

#include <XrdCksLoader.hh>

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Public Member Functions

 XrdCksLoader (XrdVersionInfo &vInfo, const char *libPath=0)
 
 ~XrdCksLoader ()
 Destructor. More...
 
XrdCksCalcLoad (const char *csName, const char *csParms=0, char *eBuff=0, int eBlen=0, bool orig=false)
 

Detailed Description

This class defines the checksum loader interface. It is intended to be used by xrootd clients to obtain an instance of a checksum calculation object. This object may be builtin or may come from a shared library.

Definition at line 42 of file XrdCksLoader.hh.

Constructor & Destructor Documentation

◆ XrdCksLoader()

XrdCksLoader::XrdCksLoader ( XrdVersionInfo &  vInfo,
const char *  libPath = 0 
)

Constructor

Parameters
vInfoIs the reference to the version information corresponding to the xrootd version you compiled with. You define this information using the XrdVERSIONINFODEF macro defined in XrdVersion.hh. You must supply your version information and it must be compatible with the loader and any shared libraries that it might load on your behalf.
libPathThe path where dynamic checksum calculators are to be found and dynamically loaded, if need be. If libPath is nil then the default loader search order is used. The name of the shared library must follow the naming convention "libXrdCksCalc<csName>.so" where <csName> is the checksum name. So, an sha256 checksum would try to load libXrdCksCalcsha256.so shared library.

Definition at line 55 of file XrdCksLoader.cc.

56 {
57  static XrdVERSIONINFODEF(myVersion, XrdCks, XrdVNUMBER, XrdVERSION);
58  static const char libSfx[] = "/libXrdCksCalc%s.so";
59  int k, n;
60 
61 // Verify that versions are compatible.
62 //
63  if (vInfo.vNum != myVersion.vNum
64  && !XrdSysPlugin::VerCmp(vInfo, myVersion, true))
65  {char buff[1024];
66  snprintf(buff, sizeof(buff), "Version %s is incompatible with %s.",
67  vInfo.vStr, myVersion.vStr);
68  verMsg = strdup(buff); urVersion = 0;
69  return;
70  }
71  urVersion = &vInfo;
72  verMsg = 0;
73 
74 // Prefill the native digests we support
75 //
76  csTab[0].Name = strdup("adler32");
77  csTab[1].Name = strdup("crc32");
78  csTab[2].Name = strdup("md5");
79  csLast = 2;
80 
81 // Record the over-ride loader path
82 //
83  if (libPath)
84  {n = strlen(libPath);
85  ldPath = (char *)malloc(n+sizeof(libSfx)+1);
86  k = (libPath[n-1] == '/');
87  strcpy(ldPath, libPath);
88  strcpy(ldPath+n, libSfx+k);
89  } else ldPath = strdup(libSfx+1);
90 }
Definition: XrdCks.hh:92
static bool VerCmp(XrdVersionInfo &vInf1, XrdVersionInfo &vInf2, bool noMsg=false)
XrdVersionInfo myVersion
XrdVERSIONINFODEF(myVersion, cmsclient, XrdVNUMBER, XrdVERSION)

References XrdCms::myVersion, XrdSysPlugin::VerCmp(), and XrdCms::XrdVERSIONINFODEF().

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◆ ~XrdCksLoader()

XrdCksLoader::~XrdCksLoader ( )

Destructor.

Definition at line 96 of file XrdCksLoader.cc.

97 {
98  int i;
99  for (i = 0; i <= csLast; i++)
100  {if (csTab[i].Name) free( csTab[i].Name);
101  if (csTab[i].Obj) csTab[i].Obj->Recycle();
102  if (csTab[i].Plugin) delete csTab[i].Plugin;
103  }
104  if (ldPath) free(ldPath);
105  if (verMsg) free(verMsg);
106 }

Member Function Documentation

◆ Load()

XrdCksCalc * XrdCksLoader::Load ( const char *  csName,
const char *  csParms = 0,
char *  eBuff = 0,
int  eBlen = 0,
bool  orig = false 
)

Get a new XrdCksCalc object that can calculate the checksum corresponding to the specified name. The object can be used to compute checksums on the fly. The object's Recycle() method must be used to delete it. The adler32, crc32, and md5 checksums are natively supported. Up to five more checksum algorithms can be loaded from shared libraries.

Parameters
csNameThe name of the checksum algorithm (e.g. md5).
csParmsAny parameters that might be needed by the checksum algorithm should it be loaded from a shared library.
eBuffOptional pointer to a buffer to receive the reason for a load failure as a null terminated string.
eBlenThe length of the buffer.
origReturns the original object not a new instance of it. This is usually used by CksManager during an autoload.
Returns
Success: A pointer to a new checksum calculation object. Failure: Zero if the corresponding checksum object could not be loaded. If eBuff was supplied, it holds the reason.

Definition at line 114 of file XrdCksLoader.cc.

116 {
117  static XrdSysMutex myMutex;
118  XrdSysMutexHelper ldMutex(myMutex);
120  XrdCksCalc *csObj;
121  XrdOucPinLoader *myPin;
122  csInfo *csIP;
123  char ldBuff[2048];
124  int n;
125 
126 // Verify that version checking succeeded
127 //
128  if (verMsg) {if (eBuff) strncpy(eBuff, verMsg, eBlen); return 0;}
129 
130 // First check if we have loaded this before
131 //
132  if ((csIP = Find(csName)))
133  {if (!(csIP->Obj))
134  { if (!strcmp("adler32", csIP->Name))
135  csIP->Obj = new XrdCksCalcadler32;
136  else if (!strcmp("crc32", csIP->Name))
137  csIP->Obj = new XrdCksCalccrc32;
138  else if (!strcmp("md5", csIP->Name))
139  csIP->Obj = new XrdCksCalcmd5;
140  else {if (eBuff) snprintf(eBuff, eBlen, "Logic error configuring %s "
141  "checksum.", csName);
142  return 0;
143  }
144  }
145  return (orig ? csIP->Obj : csIP->Obj->New());
146  }
147 
148 // Check if we can add a new entry
149 //
150  if (csLast+1 >= csMax)
151  {if (eBuff) strncpy(eBuff, "Maximum number of checksums loaded.", eBlen);
152  return 0;
153  }
154 
155 // Get the path where this object lives
156 //
157  snprintf(ldBuff, sizeof(ldBuff), ldPath, csName);
158 
159 // Get the plugin loader
160 //
161  if (!(myPin = new XrdOucPinLoader(eBuff,eBlen,urVersion,"ckslib",ldBuff)))
162  return 0;
163 
164 // Find the entry point
165 //
166  if (!(ep = (XrdCksCalc *(*)(XRDOSSCKSLIBARGS))
167  (myPin->Resolve("XrdCksCalcInit"))))
168  {myPin->Unload(true); return 0;}
169 
170 // Get the initial object
171 //
172  if (!(csObj = ep(0, 0, csName, csParms)))
173  {if (eBuff)
174  snprintf(eBuff, eBlen, "%s checksum initialization failed.", csName);
175  myPin->Unload(true);
176  return 0;
177  }
178 
179 // Verify the object
180 //
181  if (strcmp(csName, csObj->Type(n)))
182  {if (eBuff)
183  snprintf(eBuff, eBlen, "%s cksum plugin returned wrong name - %s",
184  csName, csObj->Type(n));
185  delete csObj;
186  myPin->Unload(true);
187  return 0;
188  }
189 
190 // Allocate a new entry in the table and initialize it
191 //
192  csLast++;
193  csTab[csLast].Name = strdup(csName);
194  csTab[csLast].Obj = csObj;
195  csTab[csLast].Plugin = myPin->Export();
196 
197 // Return new instance of this object
198 //
199  return (orig ? csObj : csObj->New());
200 }
#define XRDOSSCKSLIBARGS
XrdSysPlugin * Export()
void * Resolve(const char *symbl, int mcnt=1)
void Unload(bool dodel=false)

References XrdOucPinLoader::Export(), XrdOucPinLoader::Resolve(), XrdOucPinLoader::Unload(), and XRDOSSCKSLIBARGS.

Referenced by XrdCl::CheckSumManager::GetCalculator().

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The documentation for this class was generated from the following files: