Merge pull request #1813 from rouault/rfc4_network

[RFC4_dev] Add networking capabilities

1 files changed, 194 insertions, 25 deletions

diff --git a/src/open_lib.cpp b/src/open_lib.cpp
index 24c31033..cde5be7b 100644
--- a/src/open_lib.cpp
+++ b/src/open_lib.cpp
@@ -44,6 +44,7 @@
 #include "proj/internal/internal.hpp"
 
 #include "proj_internal.h"
+#include "filemanager.hpp"
 
 static const char * proj_lib_name =
 #ifdef PROJ_LIB
@@ -52,6 +53,8 @@ PROJ_LIB;
 nullptr;
 #endif
 
+using namespace NS_PROJ::internal;
+
 /************************************************************************/
 /*                           pj_set_finder()                            */
 /************************************************************************/
@@ -197,24 +200,39 @@ static const char *get_path_from_win32_projlib(const char *name, std::string& ou
 #endif
 
 /************************************************************************/
-/*                          pj_open_lib_ex()                            */
+/*                      pj_open_lib_internal()                          */
 /************************************************************************/
 
-static PAFile
-pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
-               char* out_full_filename, size_t out_full_filename_size) {
-    try {
-        std::string fname;
-        const char *sysname = nullptr;
-        PAFile fid = nullptr;
 #ifdef WIN32
-        static const char dir_chars[] = "/\\";
-        const char dirSeparator = ';';
+static const char dir_chars[] = "/\\";
+static const char dirSeparator = ';';
 #else
-        static const char dir_chars[] = "/";
-        const char dirSeparator = ':';
+static const char dir_chars[] = "/";
+static const char dirSeparator = ':';
 #endif
 
+static bool is_tilde_slash(const char* name)
+{
+    return *name == '~' && strchr(dir_chars,name[1]);
+}
+
+static bool is_rel_or_absolute_filename(const char *name)
+{
+    return strchr(dir_chars,*name)
+            || (*name == '.' && strchr(dir_chars,name[1]))
+            || (!strncmp(name, "..", 2) && strchr(dir_chars,name[2]))
+            || (name[0] != '\0' && name[1] == ':' && strchr(dir_chars,name[2]));
+}
+
+static void*
+pj_open_lib_internal(projCtx ctx, const char *name, const char *mode,
+                     void* (*open_file)(projCtx, const char*, const char*),
+                     char* out_full_filename, size_t out_full_filename_size) {
+    try {
+        std::string fname;
+        const char *sysname = nullptr;
+        void* fid = nullptr;
+
         if( ctx == nullptr ) {
             ctx = pj_get_default_ctx();
         }
@@ -223,7 +241,7 @@ pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
             out_full_filename[0] = '\0';
 
         /* check if ~/name */
-        if (*name == '~' && strchr(dir_chars,name[1]) )
+        if (is_tilde_slash(name))
             if ((sysname = getenv("HOME")) != nullptr) {
                 fname = sysname;
                 fname += DIR_CHAR;
@@ -232,11 +250,10 @@ pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
             } else
                 return nullptr;
 
-        /* or fixed path: /name, ./name or ../name */
-        else if (strchr(dir_chars,*name)
-                || (*name == '.' && strchr(dir_chars,name[1])) 
-                || (!strncmp(name, "..", 2) && strchr(dir_chars,name[2]))
-                || (name[0] != '\0' && name[1] == ':' && strchr(dir_chars,name[2])) )
+        /* or fixed path: /name, ./name or ../name or http[s]:// */
+        else if (is_rel_or_absolute_filename(name)
+                || starts_with(name, "http://")
+                || starts_with(name, "https://"))
             sysname = name;
 
         /* or try to use application provided file finder */
@@ -254,7 +271,7 @@ pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
                     fname += DIR_CHAR;
                     fname += name;
                     sysname = fname.c_str();
-                    fid = pj_ctx_fopen(ctx, sysname, mode);
+                    fid = open_file(ctx, sysname, mode);
                 } catch( const std::exception& )
                 {
                 }
@@ -270,7 +287,7 @@ pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
                 fname += DIR_CHAR;
                 fname += name;
                 sysname = fname.c_str();
-                fid = pj_ctx_fopen(ctx, sysname, mode);
+                fid = open_file(ctx, sysname, mode);
                 if( fid )
                     break;
             }
@@ -290,7 +307,7 @@ pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
         }
 
         assert(sysname); // to make Coverity Scan happy
-        if ( fid != nullptr || (fid = pj_ctx_fopen(ctx, sysname, mode)) != nullptr)
+        if ( fid != nullptr || (fid = open_file(ctx, sysname, mode)) != nullptr)
         {
             if( out_full_filename != nullptr && out_full_filename_size > 0 )
             {
@@ -322,18 +339,79 @@ pj_open_lib_ex(projCtx ctx, const char *name, const char *mode,
 }
 
 /************************************************************************/
+/*                  pj_open_file_with_manager()                         */
+/************************************************************************/
+
+static void* pj_open_file_with_manager(projCtx ctx, const char *name,
+                                       const char * /* mode */)
+{
+    return NS_PROJ::FileManager::open(ctx, name).release();
+}
+
+/************************************************************************/
+/*                 FileManager::open_resource_file()                    */
+/************************************************************************/
+
+std::unique_ptr<NS_PROJ::File> NS_PROJ::FileManager::open_resource_file(
+                                                projCtx ctx, const char *name)
+{
+    auto file = std::unique_ptr<NS_PROJ::File>(
+        reinterpret_cast<NS_PROJ::File*>(
+               pj_open_lib_internal(ctx, name, "rb",
+                                    pj_open_file_with_manager,
+                                    nullptr, 0)));
+    if( file == nullptr &&
+        !is_tilde_slash(name) &&
+        !is_rel_or_absolute_filename(name) &&
+        !starts_with(name, "http://") &&
+        !starts_with(name, "https://") &&
+        pj_context_is_network_enabled(ctx) ) {
+        std::string remote_file(pj_context_get_url_endpoint(ctx));
+        if( !remote_file.empty() ) {
+            if( remote_file.back() != '/' ) {
+                remote_file += '/';
+            }
+            remote_file += name;
+            auto pos = remote_file.rfind('.');
+            if( pos + 4 == remote_file.size() ) {
+                remote_file = remote_file.substr(0, pos) + ".tif";
+                file = open(ctx, remote_file.c_str());
+                if( file ) {
+                    pj_log( ctx, PJ_LOG_DEBUG_MAJOR,
+                            "Using %s", remote_file.c_str() );
+                    pj_ctx_set_errno( ctx, 0 );
+                }
+            }
+        }
+    }
+    return file;
+}
+
+/************************************************************************/
 /*                            pj_open_lib()                             */
 /************************************************************************/
 
+#ifndef REMOVE_LEGACY_SUPPORT
+
+// Used by following legacy function
+static void* pj_ctx_fopen_adapter(projCtx ctx, const char *name, const char *mode)
+{
+    return pj_ctx_fopen(ctx, name, mode);
+}
+
+// Legacy function
 PAFile
 pj_open_lib(projCtx ctx, const char *name, const char *mode) {
-    return pj_open_lib_ex(ctx, name, mode, nullptr, 0);
+    return (PAFile)pj_open_lib_internal(ctx, name, mode, pj_ctx_fopen_adapter, nullptr, 0);
 }
 
+#endif // REMOVE_LEGACY_SUPPORT
+
 /************************************************************************/
 /*                           pj_find_file()                             */
 /************************************************************************/
 
+
 /** Returns the full filename corresponding to a proj resource file specified
  *  as a short filename.
  * 
@@ -348,12 +426,103 @@ pj_open_lib(projCtx ctx, const char *name, const char *mode) {
 int pj_find_file(projCtx ctx, const char *short_filename,
                  char* out_full_filename, size_t out_full_filename_size)
 {
-    PAFile f = pj_open_lib_ex(ctx, short_filename, "rb", out_full_filename,
-                              out_full_filename_size);
+    auto f = reinterpret_cast<NS_PROJ::File*>(
+               pj_open_lib_internal(ctx, short_filename, "rb",
+                                    pj_open_file_with_manager,
+                                    out_full_filename,
+                                    out_full_filename_size));
     if( f != nullptr )
     {
-        pj_ctx_fclose(ctx, f);
+        delete f;
         return 1;
     }
     return 0;
 }
+
+/************************************************************************/
+/*                    pj_context_get_url_endpoint()                     */
+/************************************************************************/
+
+std::string pj_context_get_url_endpoint(PJ_CONTEXT* ctx)
+{
+    if( !ctx->endpoint.empty() ) {
+        return ctx->endpoint;
+    }
+    pj_load_ini(ctx);
+    return ctx->endpoint;
+}
+
+/************************************************************************/
+/*                              trim()                                  */
+/************************************************************************/
+
+static std::string trim(const std::string& s) {
+    const auto first = s.find_first_not_of(' ');
+    const auto last = s.find_last_not_of(' ');
+    if( first == std::string::npos || last == std::string::npos ) {
+        return std::string();
+    }
+    return s.substr(first, last - first + 1);
+}
+
+/************************************************************************/
+/*                            pj_load_ini()                             */
+/************************************************************************/
+
+void pj_load_ini(projCtx ctx)
+{
+    if( ctx->iniFileLoaded )
+        return;
+
+    const char* endpoint_from_env = getenv("PROJ_NETWORK_ENDPOINT");
+    if( endpoint_from_env && endpoint_from_env[0] != '\0' ) {
+        ctx->endpoint = endpoint_from_env;
+    }
+
+    ctx->iniFileLoaded = true;
+    auto file = std::unique_ptr<NS_PROJ::File>(
+        reinterpret_cast<NS_PROJ::File*>(
+               pj_open_lib_internal(ctx, "proj.ini", "rb",
+                                    pj_open_file_with_manager,
+                                    nullptr, 0)));
+    if( !file )
+        return;
+    file->seek(0, SEEK_END);
+    const auto filesize = file->tell();
+    if( filesize == 0 || filesize > 100 * 1024U )
+        return;
+    file->seek(0, SEEK_SET);
+    std::string content;
+    content.resize(static_cast<size_t>(filesize));
+    const auto nread = file->read(&content[0], content.size());
+    if( nread != content.size() )
+        return;
+    content += '\n';
+    size_t pos = 0;
+    while( pos != std::string::npos ) {
+        const auto eol = content.find_first_of("\r\n", pos);
+        if( eol == std::string::npos ) {
+            break;
+        }
+
+        const auto equal = content.find('=', pos);
+        if( equal < eol )
+        {
+            const auto key = trim(content.substr(pos, equal-pos));
+            const auto value = trim(content.substr(equal + 1,
+                                                    eol - (equal+1)));
+            if( ctx->endpoint.empty() && key == "cdn_endpoint" ) {
+                ctx->endpoint = value;
+            } else if ( key == "network" ) {
+                const char *enabled = getenv("PROJ_NETWORK");
+                if (enabled == nullptr || enabled[0] == '\0') {
+                    ctx->networking.enabled = ci_equal(value, "ON") ||
+                                                ci_equal(value, "YES") ||
+                                                ci_equal(value, "TRUE");
+                }
+            }
+        }
+
+        pos = content.find_first_not_of("\r\n", eol);
+    }
+}