driver.go

     1  // Copyright 2014 Google Inc. All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package driver provides an external entry point to the pprof driver.
    16  package driver
    17  
    18  import (
    19  	"io"
    20  	"maps"
    21  	"net/http"
    22  	"regexp"
    23  	"time"
    24  
    25  	internaldriver "github.com/google/pprof/internal/driver"
    26  	"github.com/google/pprof/internal/plugin"
    27  	"github.com/google/pprof/profile"
    28  )
    29  
    30  // PProf acquires a profile, and symbolizes it using a profile
    31  // manager. Then it generates a report formatted according to the
    32  // options selected through the flags package.
    33  func PProf(o *Options) error {
    34  	return internaldriver.PProf(o.internalOptions())
    35  }
    36  
    37  func (o *Options) internalOptions() *plugin.Options {
    38  	var obj plugin.ObjTool
    39  	if o.Obj != nil {
    40  		obj = &internalObjTool{o.Obj}
    41  	}
    42  	var sym plugin.Symbolizer
    43  	if o.Sym != nil {
    44  		sym = &internalSymbolizer{o.Sym}
    45  	}
    46  	var httpServer func(args *plugin.HTTPServerArgs) error
    47  	if o.HTTPServer != nil {
    48  		httpServer = func(args *plugin.HTTPServerArgs) error {
    49  			return o.HTTPServer(((*HTTPServerArgs)(args)))
    50  		}
    51  	}
    52  	return &plugin.Options{
    53  		Writer:        o.Writer,
    54  		Flagset:       o.Flagset,
    55  		Fetch:         o.Fetch,
    56  		Sym:           sym,
    57  		Obj:           obj,
    58  		UI:            o.UI,
    59  		HTTPServer:    httpServer,
    60  		HTTPTransport: o.HTTPTransport,
    61  	}
    62  }
    63  
    64  // HTTPServerArgs contains arguments needed by an HTTP server that
    65  // is exporting a pprof web interface.
    66  type HTTPServerArgs plugin.HTTPServerArgs
    67  
    68  // Options groups all the optional plugins into pprof.
    69  type Options struct {
    70  	Writer        Writer
    71  	Flagset       FlagSet
    72  	Fetch         Fetcher
    73  	Sym           Symbolizer
    74  	Obj           ObjTool
    75  	UI            UI
    76  	HTTPServer    func(*HTTPServerArgs) error
    77  	HTTPTransport http.RoundTripper
    78  }
    79  
    80  // Writer provides a mechanism to write data under a certain name,
    81  // typically a filename.
    82  type Writer interface {
    83  	Open(name string) (io.WriteCloser, error)
    84  }
    85  
    86  // A FlagSet creates and parses command-line flags.
    87  // It is similar to the standard flag.FlagSet.
    88  type FlagSet interface {
    89  	// Bool, Int, Float64, and String define new flags,
    90  	// like the functions of the same name in package flag.
    91  	Bool(name string, def bool, usage string) *bool
    92  	Int(name string, def int, usage string) *int
    93  	Float64(name string, def float64, usage string) *float64
    94  	String(name string, def string, usage string) *string
    95  
    96  	// StringList is similar to String but allows multiple values for a
    97  	// single flag
    98  	StringList(name string, def string, usage string) *[]*string
    99  
   100  	// ExtraUsage returns any additional text that should be printed after the
   101  	// standard usage message. The extra usage message returned includes all text
   102  	// added with AddExtraUsage().
   103  	// The typical use of ExtraUsage is to show any custom flags defined by the
   104  	// specific pprof plugins being used.
   105  	ExtraUsage() string
   106  
   107  	// AddExtraUsage appends additional text to the end of the extra usage message.
   108  	AddExtraUsage(eu string)
   109  
   110  	// Parse initializes the flags with their values for this run
   111  	// and returns the non-flag command line arguments.
   112  	// If an unknown flag is encountered or there are no arguments,
   113  	// Parse should call usage and return nil.
   114  	Parse(usage func()) []string
   115  }
   116  
   117  // A Fetcher reads and returns the profile named by src, using
   118  // the specified duration and timeout. It returns the fetched
   119  // profile and a string indicating a URL from where the profile
   120  // was fetched, which may be different than src.
   121  type Fetcher interface {
   122  	Fetch(src string, duration, timeout time.Duration) (*profile.Profile, string, error)
   123  }
   124  
   125  // A Symbolizer introduces symbol information into a profile.
   126  type Symbolizer interface {
   127  	Symbolize(mode string, srcs MappingSources, prof *profile.Profile) error
   128  }
   129  
   130  // MappingSources map each profile.Mapping to the source of the profile.
   131  // The key is either Mapping.File or Mapping.BuildId.
   132  type MappingSources map[string][]struct {
   133  	Source string // URL of the source the mapping was collected from
   134  	Start  uint64 // delta applied to addresses from this source (to represent Merge adjustments)
   135  }
   136  
   137  // An ObjTool inspects shared libraries and executable files.
   138  type ObjTool interface {
   139  	// Open opens the named object file. If the object is a shared
   140  	// library, start/limit/offset are the addresses where it is mapped
   141  	// into memory in the address space being inspected. If the object
   142  	// is a linux kernel, relocationSymbol is the name of the symbol
   143  	// corresponding to the start address.
   144  	Open(file string, start, limit, offset uint64, relocationSymbol string) (ObjFile, error)
   145  
   146  	// Disasm disassembles the named object file, starting at
   147  	// the start address and stopping at (before) the end address.
   148  	Disasm(file string, start, end uint64, intelSyntax bool) ([]Inst, error)
   149  }
   150  
   151  // An Inst is a single instruction in an assembly listing.
   152  type Inst struct {
   153  	Addr     uint64 // virtual address of instruction
   154  	Text     string // instruction text
   155  	Function string // function name
   156  	File     string // source file
   157  	Line     int    // source line
   158  }
   159  
   160  // An ObjFile is a single object file: a shared library or executable.
   161  type ObjFile interface {
   162  	// Name returns the underlying file name, if available.
   163  	Name() string
   164  
   165  	// ObjAddr returns the objdump address corresponding to a runtime address.
   166  	ObjAddr(addr uint64) (uint64, error)
   167  
   168  	// BuildID returns the GNU build ID of the file, or an empty string.
   169  	BuildID() string
   170  
   171  	// SourceLine reports the source line information for a given
   172  	// address in the file. Due to inlining, the source line information
   173  	// is in general a list of positions representing a call stack,
   174  	// with the leaf function first.
   175  	SourceLine(addr uint64) ([]Frame, error)
   176  
   177  	// Symbols returns a list of symbols in the object file.
   178  	// If r is not nil, Symbols restricts the list to symbols
   179  	// with names matching the regular expression.
   180  	// If addr is not zero, Symbols restricts the list to symbols
   181  	// containing that address.
   182  	Symbols(r *regexp.Regexp, addr uint64) ([]*Sym, error)
   183  
   184  	// Close closes the file, releasing associated resources.
   185  	Close() error
   186  }
   187  
   188  // A Frame describes a single line in a source file.
   189  type Frame struct {
   190  	Func      string // name of function
   191  	File      string // source file name
   192  	Line      int    // line in file
   193  	Column    int    // column in file
   194  	StartLine int    // start line of function (if available)
   195  }
   196  
   197  // A Sym describes a single symbol in an object file.
   198  type Sym struct {
   199  	Name  []string // names of symbol (many if symbol was dedup'ed)
   200  	File  string   // object file containing symbol
   201  	Start uint64   // start virtual address
   202  	End   uint64   // virtual address of last byte in sym (Start+size-1)
   203  }
   204  
   205  // A UI manages user interactions.
   206  type UI interface {
   207  	// ReadLine returns a line of text (a command) read from the user.
   208  	// prompt is printed before reading the command.
   209  	ReadLine(prompt string) (string, error)
   210  
   211  	// Print shows a message to the user.
   212  	// It formats the text as fmt.Print would and adds a final \n if not already present.
   213  	// For line-based UI, Print writes to standard error.
   214  	// (Standard output is reserved for report data.)
   215  	Print(...interface{})
   216  
   217  	// PrintErr shows an error message to the user.
   218  	// It formats the text as fmt.Print would and adds a final \n if not already present.
   219  	// For line-based UI, PrintErr writes to standard error.
   220  	PrintErr(...interface{})
   221  
   222  	// IsTerminal returns whether the UI is known to be tied to an
   223  	// interactive terminal (as opposed to being redirected to a file).
   224  	IsTerminal() bool
   225  
   226  	// WantBrowser indicates whether browser should be opened with the -http option.
   227  	WantBrowser() bool
   228  
   229  	// SetAutoComplete instructs the UI to call complete(cmd) to obtain
   230  	// the auto-completion of cmd, if the UI supports auto-completion at all.
   231  	SetAutoComplete(complete func(string) string)
   232  }
   233  
   234  // internalObjTool is a wrapper to map from the pprof external
   235  // interface to the internal interface.
   236  type internalObjTool struct {
   237  	ObjTool
   238  }
   239  
   240  func (o *internalObjTool) Open(file string, start, limit, offset uint64, relocationSymbol string) (plugin.ObjFile, error) {
   241  	f, err := o.ObjTool.Open(file, start, limit, offset, relocationSymbol)
   242  	if err != nil {
   243  		return nil, err
   244  	}
   245  	return &internalObjFile{f}, err
   246  }
   247  
   248  type internalObjFile struct {
   249  	ObjFile
   250  }
   251  
   252  func (f *internalObjFile) SourceLine(frame uint64) ([]plugin.Frame, error) {
   253  	frames, err := f.ObjFile.SourceLine(frame)
   254  	if err != nil {
   255  		return nil, err
   256  	}
   257  	var pluginFrames []plugin.Frame
   258  	for _, f := range frames {
   259  		pluginFrames = append(pluginFrames, plugin.Frame(f))
   260  	}
   261  	return pluginFrames, nil
   262  }
   263  
   264  func (f *internalObjFile) Symbols(r *regexp.Regexp, addr uint64) ([]*plugin.Sym, error) {
   265  	syms, err := f.ObjFile.Symbols(r, addr)
   266  	if err != nil {
   267  		return nil, err
   268  	}
   269  	var pluginSyms []*plugin.Sym
   270  	for _, s := range syms {
   271  		ps := plugin.Sym(*s)
   272  		pluginSyms = append(pluginSyms, &ps)
   273  	}
   274  	return pluginSyms, nil
   275  }
   276  
   277  func (o *internalObjTool) Disasm(file string, start, end uint64, intelSyntax bool) ([]plugin.Inst, error) {
   278  	insts, err := o.ObjTool.Disasm(file, start, end, intelSyntax)
   279  	if err != nil {
   280  		return nil, err
   281  	}
   282  	var pluginInst []plugin.Inst
   283  	for _, inst := range insts {
   284  		pluginInst = append(pluginInst, plugin.Inst(inst))
   285  	}
   286  	return pluginInst, nil
   287  }
   288  
   289  // internalSymbolizer is a wrapper to map from the pprof external
   290  // interface to the internal interface.
   291  type internalSymbolizer struct {
   292  	Symbolizer
   293  }
   294  
   295  func (s *internalSymbolizer) Symbolize(mode string, srcs plugin.MappingSources, prof *profile.Profile) error {
   296  	isrcs := MappingSources{}
   297  	maps.Copy(isrcs, srcs)
   298  	return s.Symbolizer.Symbolize(mode, isrcs, prof)
   299  }
   300
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